sparc32: add ucmpdi2

Based on copy from microblaze add ucmpdi2 implementation.
This fixes build of niu driver which failed with:

drivers/built-in.o: In function `niu_get_nfc':
niu.c:(.text+0x91494): undefined reference to `__ucmpdi2'

This driver will never be used on a sparc32 system,
but patch added to fix build breakage with all*config builds.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/lib/ucmpdi2.c b/arch/sparc/lib/ucmpdi2.c
new file mode 100644
index 0000000..1e06ed5
--- /dev/null
+++ b/arch/sparc/lib/ucmpdi2.c
@@ -0,0 +1,19 @@
+#include <linux/module.h>
+#include "libgcc.h"
+
+word_type __ucmpdi2(unsigned long long a, unsigned long long b)
+{
+	const DWunion au = {.ll = a};
+	const DWunion bu = {.ll = b};
+
+	if ((unsigned int) au.s.high < (unsigned int) bu.s.high)
+		return 0;
+	else if ((unsigned int) au.s.high > (unsigned int) bu.s.high)
+		return 2;
+	if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
+		return 0;
+	else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
+		return 2;
+	return 1;
+}
+EXPORT_SYMBOL(__ucmpdi2);