ARC: [BE] Select correct CROSS_COMPILE prefix

This allows CONFIG_CPU_BIG_ENDIAN=y to build correctly out of the box,
w/o any other tweaks.

Cc: Noam Camus <noamc@ezchip.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Anton Kolesov <akolesov@synosys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/Makefile

@@ -9,7 +9,11 @@
 UTS_MACHINE := arc
 
 ifeq ($(CROSS_COMPILE),)
+ifndef CONFIG_CPU_BIG_ENDIAN
 CROSS_COMPILE := arc-linux-
+else
+CROSS_COMPILE := arceb-linux-
+endif
 endif
 
 KBUILD_DEFCONFIG := nsim_700_defconfig