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/gpio/stm32_gpio.c b/drivers/st/gpio/stm32_gpio.c
index 44d7c09..2d64de3 100644
--- a/drivers/st/gpio/stm32_gpio.c
+++ b/drivers/st/gpio/stm32_gpio.c
@@ -282,7 +282,7 @@
 
 	clk_disable(clock);
 
-#if STM32MP13 || STM32MP15
+#ifdef STM32MP1X
 	if (status == DT_SECURE) {
 		stm32mp_register_secure_gpio(bank, pin);
 #if !IMAGE_BL2