sparc: Set UTS_MACHINE correctly.

"ARCH" can be just about anything, so we shouldn't end up
with UTS_MACHINE of "sparc" in a 64-bit kernel build just
because someone set the personality using 'sparc32' or
similar.  CONFIG_SPARC64 drives the compilation and
therefore provides the definitive value, not "ARCH".

This mirrors commit 8c6531f7
(x86: correctly set UTS_MACHINE for "make ARCH=x86")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc/Makefile

@@ -27,6 +27,7 @@ AS             := $(AS) -32
 LDFLAGS        := -m elf32_sparc
 CHECKFLAGS     += -D__sparc__
 export BITS    := 32
+UTS_MACHINE    := sparc
 
 #KBUILD_CFLAGS += -g -pipe -fcall-used-g5 -fcall-used-g7
 KBUILD_CFLAGS += -m32 -pipe -mno-fpu -fcall-used-g5 -fcall-used-g7
@@ -46,6 +47,7 @@ CHECKFLAGS      += -D__sparc__ -D__sparc_v9__ -D__arch64__ -m64
 
 LDFLAGS              := -m elf64_sparc
 export BITS          := 64
+UTS_MACHINE          := sparc64
 
 KBUILD_CFLAGS += -m64 -pipe -mno-fpu -mcpu=ultrasparc -mcmodel=medlow   \
                  -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare \