mk/config.mk.in: enable SMP on ARMv7+ (Trac #12981)

Before the change result of expression
    ArchSupportsSMP="$(if $(filter $(ARM_ISA),ARMv5 ARMv6),NO,YES)"
to evaluate to
    ArchSupportsSMP="YES"

After the change it's
    ArchSupportsSMP=YES

Thanks to orion for the fix!

Fixes Trac #12981
Signed-off-by: Sergei Trofimovich <siarheit@google.com>

mk/config.mk.in

@@ -187,7 +187,7 @@ HaveLibDL = @HaveLibDL@
 # includes/stg/SMP.h
 ifeq "$(TargetArch_CPP)" "arm"
 # We don't support load/store barriers pre-ARMv7. See #10433.
-ArchSupportsSMP="$(if $(filter $(ARM_ISA),ARMv5 ARMv6),NO,YES)"
+ArchSupportsSMP=$(if $(filter $(ARM_ISA),ARMv5 ARMv6),NO,YES)
 else
 ArchSupportsSMP=$(strip $(patsubst $(TargetArch_CPP), YES, $(findstring $(TargetArch_CPP), i386 x86_64 sparc powerpc powerpc64 powerpc64le aarch64)))
 endif