arm: Rename STM32MP15x

CONFIG options must not use lower-case letter. Convert this and related
ones to upper case.

Signed-off-by: Simon Glass <sjg@chromium.org
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/configs/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig
index ec32f1e..84b0854 100644
--- a/configs/stm32mp15_trusted_defconfig
+++ b/configs/stm32mp15_trusted_defconfig
@@ -9,8 +9,8 @@
 CONFIG_DDR_CACHEABLE_SIZE=0x10000000
 CONFIG_CMD_STM32KEY=y
 CONFIG_TYPEC_STUSB160X=y
-CONFIG_STM32MP15x_STM32IMAGE=y
-CONFIG_TARGET_ST_STM32MP15x=y
+CONFIG_STM32MP15X_STM32IMAGE=y
+CONFIG_TARGET_ST_STM32MP15X=y
 CONFIG_ENV_OFFSET_REDUND=0x2C0000
 CONFIG_CMD_STM32PROG=y
 # CONFIG_ARMV7_NONSEC is not set