arm64: ls1028a: remove fdt_high environment variable

Setting fdt_high and initrd_high to 0xffffffffffffffff leads to
various difficulty to resolve bugs.
Remove them and use bootm_size instead to safely contain a kernel,
device tree and initrd for relocation.

Signed-off-by: Yuantian Tang <andy.tang@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/include/configs/ls1028a_common.h b/include/configs/ls1028a_common.h
index 05b8cf0..1c7680c 100644
--- a/include/configs/ls1028a_common.h
+++ b/include/configs/ls1028a_common.h
@@ -79,8 +79,7 @@
 	"hwconfig=fsl_ddr:bank_intlv=auto\0"	\
 	"ramdisk_addr=0x800000\0"		\
 	"ramdisk_size=0x2000000\0"		\
-	"fdt_high=0xffffffffffffffff\0"		\
-	"initrd_high=0xffffffffffffffff\0"	\
+	"bootm_size=0x10000000\0"		\
 	"fdt_addr=0x00f00000\0"                 \
 	"kernel_addr=0x01000000\0"              \
 	"scriptaddr=0x80000000\0"               \
diff --git a/include/configs/ls1028aqds.h b/include/configs/ls1028aqds.h
index 982df07..fca0a3a 100644
--- a/include/configs/ls1028aqds.h
+++ b/include/configs/ls1028aqds.h
@@ -90,8 +90,6 @@
 	"hwconfig=fsl_ddr:bank_intlv=auto\0" \
 	"ramdisk_addr=0x800000\0" \
 	"ramdisk_size=0x2000000\0" \
-	"fdt_high=0xffffffffffffffff\0" \
-	"initrd_high=0xffffffffffffffff\0" \
 	"fdt_addr=0x00f00000\0" \
 	"kernel_addr=0x01000000\0" \
 	"scriptaddr=0x80000000\0" \