sh: Add support for SH2A freestanding build

SH2A toolchains often only provide an fdpic version of libgcc. This
can't be used with bare-metal software like U-Boot, so this patch
provides the necessary functions extracted from libgcc.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/arch/sh/lib/lshrdi3.c b/arch/sh/lib/lshrdi3.c
new file mode 100644
index 0000000..bb340ac
--- /dev/null
+++ b/arch/sh/lib/lshrdi3.c
@@ -0,0 +1,25 @@
+#include "libgcc.h"
+
+long long __lshrdi3(long long u, word_type b)
+{
+	DWunion uu, w;
+	word_type bm;
+
+	if (b == 0)
+		return u;
+
+	uu.ll = u;
+	bm = 32 - b;
+
+	if (bm <= 0) {
+		w.s.high = 0;
+		w.s.low = (unsigned int) uu.s.high >> -bm;
+	} else {
+		const unsigned int carries = (unsigned int) uu.s.high << bm;
+
+		w.s.high = (unsigned int) uu.s.high >> b;
+		w.s.low = ((unsigned int) uu.s.low >> b) | carries;
+	}
+
+	return w.ll;
+}