imx: imx8mm_evk: Switch to BOOTSTD

Move env to imx8mm_evk.env
Switch to support BOOTSTD with a bsp bootcmd as fallback.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/imx8m/Kconfig b/arch/arm/mach-imx/imx8m/Kconfig
index 0cf3c1b..28be6a2 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -154,6 +154,8 @@
 	select FSL_CAAM
 	select SPL_CRYPTO if SPL
 	imply OF_UPSTREAM
+	imply BOOTSTD_FULL
+	imply BOOTSTD_BOOTCOMMAND
 
 config TARGET_IMX8MN_DDR4_EVK
 	bool "imx8mn DDR4 EVK board"
@@ -163,6 +165,8 @@
 	select FSL_CAAM
 	select SPL_CRYPTO if SPL
 	imply OF_UPSTREAM
+	imply BOOTSTD_FULL
+	imply BOOTSTD_BOOTCOMMAND
 
 config TARGET_IMX8MN_VENICE
 	bool "Support Gateworks Venice iMX8M Nano module"