configs: stm32h7xx: Migrate CONFIG_CMD_CACHE to defconfig

Remove CONFIG_CMD_CACHE from include/configs/stm32h7xx.h
and enable it in stm32h7xx_defconfig

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/configs/stm32h743-disco_defconfig b/configs/stm32h743-disco_defconfig
index c6a0d10..67c754b 100644
--- a/configs/stm32h743-disco_defconfig
+++ b/configs/stm32h743-disco_defconfig
@@ -19,6 +19,7 @@
 CONFIG_CMD_GPT=y
 CONFIG_CMD_MMC=y
 # CONFIG_CMD_SETEXPR is not set
+CONFIG_CMD_CACHE=y
 CONFIG_CMD_TIMER=y
 CONFIG_CMD_EXT2=y
 CONFIG_CMD_EXT4=y