Silicon/Rockchip: RkSdmmcDxe: Set base clock rate

If a card was plugged in after boot, it wouldn't respond.
Turns out we need to increase the base clock from the default 400 KHz. Set it to
52 MHz like the earlier stages do when a card is present at boot.

Weirdly enough this arised only after I globally enabled the DEBUG_INFO logging
level.

edk2-rockchip/Silicon/Rockchip/Drivers/RkSdmmcDxe/RkSdmmcDxe.c

@@ -86,7 +86,7 @@ STATIC DW_MMC_HC_SLOT_CAP mDwMmcCapability = {
   .SlotType    = RemovableSlot,
   .CardType    = SdCardType,
   .Voltage30   = 1,
-  .BaseClkFreq = 3200
+  .BaseClkFreq = 52000
 };
 
 STATIC
@@ -147,6 +147,8 @@ RkSdmmcDxeInitialize (
 
   RkSdmmcSetIoMux ();
 
+  RkSdmmcSetClockRate (mDwMmcCapability.BaseClkFreq * 1000);
+
   Status = gBS->InstallMultipleProtocolInterfaces(&mDwMmcCapability.Controller,
             &gEfiDevicePathProtocolGuid, &mDwMmcDevice.DevicePath,
             &gEdkiiNonDiscoverableDeviceProtocolGuid, &mDwMmcDevice.Device,