powerpc: Provide __bswapdi2

Some versions of GCC apparently expect this to be provided by libgcc.

Updates from Mikey to fix 32 bit version and adding "r" to registers.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 5cfa800..6820e45 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -234,6 +234,17 @@
 	isync
 	blr
 
+_GLOBAL(__bswapdi2)
+	srdi	r8,r3,32
+	rlwinm	r7,r3,8,0xffffffff
+	rlwimi	r7,r3,24,0,7
+	rlwinm	r9,r8,8,0xffffffff
+	rlwimi	r7,r3,24,16,23
+	rlwimi	r9,r8,24,0,7
+	rlwimi	r9,r8,24,16,23
+	sldi	r7,r7,32
+	or	r3,r7,r9
+	blr
 
 #if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
 /*