STMicro: STM32U5: add SVD files

[zkrx]

Taken from [1], "STM32U5 System View Description" V1.3 27 Sep 2023.

.
└── STM32U5_svd
    ├── _htmresc
    │   └── st_logo.png
    ├── Release_Notes_files
    │   ├── colorschememapping.xml
    │   ├── filelist.xml
    │   └── themedata.thmx
    ├── Release_Notes.htm
    └── STM32U5_svd_V1.3
	├── STM32U535.svd
	├── STM32U545.svd
	├── STM32U575.svd
	├── STM32U585.svd
	├── STM32U595.svd
	├── STM32U599.svd
	├── STM32U5A5.svd
	├── STM32U5A9.svd
	├── STM32U5Fx.svd
	└── STM32U5Gx.svd

[1] https://www.st.com/en/microcontrollers-microprocessors/stm32u5-series.html#cad-resources