ARC: enable CONFIG_SYS_BOOT_RAMDISK_HIGH

This enables relocation of initrd to the end of available DDR before Linux
kernel start-up as it is done in other architectures.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

arch/arc/include/asm/config.h

@@ -8,6 +8,7 @@
 #define __ASM_ARC_CONFIG_H_
 
 #define CONFIG_SYS_GENERIC_GLOBAL_DATA
+#define CONFIG_SYS_BOOT_RAMDISK_HIGH
 
 #define CONFIG_LMB