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/include/drivers/st/stm32mp_ddr.h b/include/drivers/st/stm32mp_ddr.h
index 57b0668..970ff19 100644
--- a/include/drivers/st/stm32mp_ddr.h
+++ b/include/drivers/st/stm32mp_ddr.h
@@ -28,7 +28,7 @@
 struct stm32mp_ddr_reg_desc {
 	uint16_t offset;	/* Offset for base address */
 	uint8_t par_offset;	/* Offset for parameter array */
-#if !STM32MP13 && !STM32MP15
+#ifdef STM32MP2X
 	bool qd; /* quasi-dynamic register if true */
 #endif
 };