Removal of unused 6.1 and 5.15 kernels

Removing the following unused kernels for diff patches:
- linux-intel-lts2021
- linux-intel-lts2022
- lts2021-chromium
- lts2022-chromium

Tests done:
- Android CIV
- Wi-Fi on/off/scan
- Bluetooth on/off/scan
- Camera capture/recording
- adb reboot
- adb remount in CIV

Tracked-On: OAM-124501
Signed-off-by: simonami99 <[email protected]>

bsp_diff/common/device/intel/project-celadon/caas/0002-WA-Disable-trusty-for-MTL-BM-Boot.patch

@@ -1,4 +1,4 @@
-From bf9c7ad76c74186744a6aa7f02fd3bcd74dc7dd3 Mon Sep 17 00:00:00 2001
+From 8d89450b45e98b9cc74bfbe1023f463d272700a0 Mon Sep 17 00:00:00 2001
 From: Tanuj Tekriwal <[email protected]>
 Date: Thu, 4 Jul 2024 03:30:20 +0000
 Subject: [PATCH] WA Disable trusty for MTL BM Boot
@@ -14,12 +14,12 @@ Signed-off-by: Tanuj Tekriwal <[email protected]>
  1 file changed, 4 insertions(+), 4 deletions(-)
 
 diff --git a/caas/mixins.spec b/caas/mixins.spec
-index 18312100..b43571ee 100755
+index 687b92f8..53a7b04f 100755
 --- a/caas/mixins.spec
 +++ b/caas/mixins.spec
 @@ -9,7 +9,7 @@ product.mk: device.mk
  [groups]
- kernel: gmin64(useprebuilt=false,src_path=kernel/lts2023-chromium, loglevel=7, interactive_governor=false, relative_sleepstates=false, modules_in_bootimg=false, external_modules=,debug_modules=, use_bcmdhd=false, use_iwlwifi=false, extmod_platform=bxt, iwl_defconfig=, cfg_path=config-lts/lts2023-chromium, more_modules=true, lts2021_chromium_src_path=kernel/lts2021-chromium, lts2021_chromium_cfg_path=config-lts/lts2021-chromium, linux_intel_lts2021_src_path=kernel/linux-intel-lts2021, linux_intel_lts2021_cfg_path=config-lts/linux-intel-lts2021, lts2022_chromium_src_path=kernel/lts2022-chromium, lts2022_chromium_cfg_path=config-lts/lts2022-chromium, linux_intel_lts2022_src_path=kernel/linux-intel-lts2022, linux_intel_lts2022_cfg_path=config-lts/linux-intel-lts2022)
+ kernel: gmin64(useprebuilt=false,src_path=kernel/lts2023-chromium, loglevel=7, interactive_governor=false, relative_sleepstates=false, modules_in_bootimg=false, external_modules=,debug_modules=, use_bcmdhd=false, use_iwlwifi=false, extmod_platform=bxt, iwl_defconfig=, cfg_path=config-lts/lts2023-chromium, more_modules=true,lts2023_chromium_src_path=kernel/lts2023-chromium, lts2023_chromium_cfg_path=config-lts/lts2023-chromium, linux_intel_lts2023_src_path=kernel/linux-intel-lts2023, linux_intel_lts2023_cfg_path=config-lts/linux-intel-lts2023)
  disk-bus: auto
 -boot-arch: project-celadon(uefi_arch=x86_64,fastboot=efi,ignore_rsci=true,disable_watchdog=true,watchdog_parameters=10 30,verity_warning=false,txe_bind_root_of_trust=false,bootloader_block_size=4096,verity_mode=false,disk_encryption=false,file_encryption=true,metadata_encryption=true,fsverity=true,target=caas,ignore_not_applicable_reset=true,self_usb_device_mode_protocol=true,usb_storage=true,live_boot=true,userdata_checkpoint=true,data_use_f2fs=true,trusty=true)
 +boot-arch: project-celadon(uefi_arch=x86_64,fastboot=efi,ignore_rsci=true,disable_watchdog=true,watchdog_parameters=10 30,verity_warning=false,txe_bind_root_of_trust=false,bootloader_block_size=4096,verity_mode=false,disk_encryption=false,file_encryption=true,metadata_encryption=true,fsverity=true,target=caas,ignore_not_applicable_reset=true,self_usb_device_mode_protocol=true,usb_storage=true,live_boot=true,userdata_checkpoint=true,data_use_f2fs=true)