configs: mx23_olinuxino_defconfig: disable bootefi command

CONFIG_CMD_BOOTEFI is enabled by Kconfig default, but rarely
used on this board/platform.
So let's disable it for the boards default config.
This also saves around 16 KiB in the final u-boot.sb.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>
diff --git a/configs/mx23_olinuxino_defconfig b/configs/mx23_olinuxino_defconfig
index bc34a3e..0e552a6 100644
--- a/configs/mx23_olinuxino_defconfig
+++ b/configs/mx23_olinuxino_defconfig
@@ -14,6 +14,7 @@
 CONFIG_ARCH_MISC_INIT=y
 # CONFIG_SPL_FRAMEWORK is not set
 CONFIG_HUSH_PARSER=y
+# CONFIG_CMD_BOOTEFI is not set
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_MMC=y