mn10300: define __fls

Like fls, but can't be handed 0 and returns the bit number.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

include/asm-mn10300/bitops.h

@@ -195,6 +195,17 @@ int fls(int x)
 	return (x != 0) ? __ilog2_u32(x) + 1 : 0;
 }
 
+/**
+ * __fls - find last (most-significant) set bit in a long word
+ * @word: the word to search
+ *
+ * Undefined if no set bit exists, so code should check against 0 first.
+ */
+static inline unsigned long __fls(unsigned long word)
+{
+	return __ilog2_u32(word);
+}
+
 /**
  * ffs - find first bit set
  * @x: the word to search