arc: remove redundant UTS_MACHINE define in arch/arc/Makefile

The top-level Makefile sets the default of UTS_MACHINE to $(ARCH).

If ARCH and UTS_MACHINE match, arch/$(ARCH)/Makefile need not specify
UTS_MACHINE explicitly.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/Makefile

@@ -6,8 +6,6 @@
 # published by the Free Software Foundation.
 #
 
-UTS_MACHINE := arc
-
 ifeq ($(CROSS_COMPILE),)
 ifndef CONFIG_CPU_BIG_ENDIAN
 CROSS_COMPILE := arc-linux-