variants(h5): add generic STM32H503CB support #629

Job	Run time
Check CMake usage (NUCLEO_F091RC)	43s
Check CMake usage (NUCLEO_F103RB)	38s
Check CMake usage (NUCLEO_F207ZG)	45s
Check CMake usage (NUCLEO_F303RE)	42s
Check CMake usage (NUCLEO_F411RE)	41s
Check CMake usage (NUCLEO_F767ZI)	42s
Check CMake usage (NUCLEO_G0B1RE)	41s
Check CMake usage (NUCLEO_G474RE)	41s
Check CMake usage (NUCLEO_H563ZI)	52s
Check CMake usage (NUCLEO_H743ZI2)	45s
Check CMake usage (NUCLEO_L073RZ)	47s
Check CMake usage (NUCLEO_L152RE)	38s
Check CMake usage (NUCLEO_L476RG)	43s
Check CMake usage (NUCLEO_L552ZE_Q)	50s
Check CMake usage (NUCLEO_U575ZI_Q)	46s
Check CMake usage (P_NUCLEO_WB55RG)	35s
Check CMake usage (NUCLEO_WBA55CG)	34s
Check CMake usage (NUCLEO_WL55JC1)	32s
	12m 35s

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