ARC: [*defconfig] No need to specify CONFIG_CROSS_COMPILE

ARC: [*defconfig] No need to specify CONFIG_CROSS_COMPILE

The problem is with CONFIG_CPU_BIG_ENDIAN=y we still needed .config
fixup to override the the defconfig prefix to arceb-linux-

So remove these from defconfig and let user pass this via CROSS_COMPILE
environment var or use the default for ENDIAN (per previous patch)

No other arch carries them in defconfigs anyways !

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>