imx: imx8qm: enable relocation of fdt and initrd

Set CONFIG_SYS_BOOTMAPSZ to the amount of memory available which is needed
to relocate the kernel, device tree and initrd.

Remove 'fdt_high' and 'initrd_high' environment variables from default
environment which prevents relocation of FDT and initrd.

Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Ye Li <ye.li@nxp.com>
Cc: uboot-imx <uboot-imx@nxp.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/imx8qm_rom7720.h b/include/configs/imx8qm_rom7720.h
index 8e1427d..ac25549 100644
--- a/include/configs/imx8qm_rom7720.h
+++ b/include/configs/imx8qm_rom7720.h
@@ -17,6 +17,7 @@
 #undef CONFIG_BOOTM_NETBSD
 
 #define CONFIG_FSL_USDHC
+#define CONFIG_SYS_BOOTMAPSZ		(256 << 20)
 #define CONFIG_SYS_FSL_ESDHC_ADDR	0
 #define USDHC1_BASE_ADDR		0x5B010000
 #define USDHC2_BASE_ADDR		0x5B020000
@@ -67,11 +68,9 @@
 	"panel=NULL\0" \
 	"console=ttyLP0\0" \
 	"fdt_addr=0x83000000\0"			\
-	"fdt_high=0xffffffffffffffff\0"		\
 	"boot_fdt=try\0" \
 	"fdt_file=imx8qm-rom7720-a1.dtb\0" \
 	"initrd_addr=0x83800000\0"		\
-	"initrd_high=0xffffffffffffffff\0" \
 	"mmcdev="__stringify(CONFIG_SYS_MMC_ENV_DEV)"\0" \
 	"mmcpart=" __stringify(CONFIG_SYS_MMC_IMG_LOAD_PART) "\0" \
 	"mmcroot=" CONFIG_MMCROOT " rootwait rw\0" \