feat(st): introduce SoC family compilation switch

add STM32MP1X and STM3MP2X compilation switch to replace
#if STM32MP21 || STM32MP23 || STM32MP25 for MP2 SoCs and
#if STM32MP13 || STM32MP15 for MP1 SoCs.

This will avoid to forget to modify all these files when a new SoC is
introduced.

Change-Id: Ib984b22a19e08af5bc1b62fe2032f10240ec9122
Signed-off-by: Maxime Méré <maxime.mere@foss.st.com>
diff --git a/drivers/st/mmc/stm32_sdmmc2.c b/drivers/st/mmc/stm32_sdmmc2.c
index 66988d7..e07d9e7 100644
--- a/drivers/st/mmc/stm32_sdmmc2.c
+++ b/drivers/st/mmc/stm32_sdmmc2.c
@@ -129,7 +129,7 @@
 #define DT_SDMMC2_COMPAT		"st,stm32-sdmmc2"
 #endif
 
-#if STM32MP13 || STM32MP15
+#ifdef STM32MP1X
 #define SDMMC_FIFO_SIZE			64U
 #else
 #define SDMMC_FIFO_SIZE			1024U