imx: imx8mq_evk: Switch to BOOTSTD

Move env to imx8mq_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 28be6a2..76a8be7 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -54,6 +54,8 @@
 	select ARCH_MISC_INIT
 	select SPL_CRYPTO if SPL
 	imply OF_UPSTREAM
+	imply BOOTSTD_FULL
+	imply BOOTSTD_BOOTCOMMAND
 
 config TARGET_IMX8MQ_PHANBELL
 	bool "imx8mq_phanbell"