configs: librem5: enable ENV_VARS_UBOOT_RUNTIME_CONFIG

Enable the runtime config so that we can store the board name and rev in
the environment.
Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>

configs/librem5_defconfig

@@ -88,4 +88,5 @@ CONFIG_IMX8M_DRAM=y
 CONFIG_IMX8M_LPDDR4=y
 
 CONFIG_ENV_IS_IN_MMC=y
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 

include/configs/librem5.h

@@ -67,8 +67,6 @@
 #define CONFIG_SYS_I2C_MXC_I2C3		/* enable I2C bus 3 */
 #define CONFIG_SYS_I2C_MXC_I2C4		/* enable I2C bus 4 */
 
-#define CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
-
 #define CONFIG_POWER
 #define CONFIG_POWER_I2C
 #define CONFIG_POWER_BD71837