ARM: stm32: Enable bootd, iminfo, imxtract on DHCOM

Enable these standard U-Boot commands for image manipulation and for
starting the default boot command using 'boot' command in U-Boot shell.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: NPatrick Delaunay <patrick.delaunay@st.com>

configs/stm32mp15_dhcom_basic_defconfig

@@ -19,10 +19,7 @@ CONFIG_SPL_MTD_SUPPORT=y
 CONFIG_SPL_POWER_SUPPORT=y
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x80000
 CONFIG_SYS_PROMPT="STM32MP> "
-# CONFIG_CMD_BOOTD is not set
 # CONFIG_CMD_ELF is not set
-# CONFIG_CMD_IMI is not set
-# CONFIG_CMD_XIMG is not set
 # CONFIG_CMD_EXPORTENV is not set
 CONFIG_CMD_EEPROM=y
 CONFIG_CMD_MEMINFO=y