powerpc: Remove __ilog2_u64 and ffs4 from bitops

Remove __ilog2_u64 and ffs4 from powerpc bitops to align with the
kernel implementation.

Use the generic __ffs64 instead of a custom powerpc implementation.

Cc: York Sun <yorksun@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/arch/powerpc/cpu/mpc8xxx/law.c b/arch/powerpc/cpu/mpc8xxx/law.c
index 33d53a8..24baad4 100644
--- a/arch/powerpc/cpu/mpc8xxx/law.c
+++ b/arch/powerpc/cpu/mpc8xxx/law.c
@@ -11,6 +11,7 @@
 #include <linux/compiler.h>
 #include <asm/fsl_law.h>
 #include <asm/io.h>
+#include <linux/log2.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -187,7 +188,7 @@
 	if (start == 0)
 		start_align = 1ull << (LAW_SIZE_32G + 1);
 	else
-		start_align = 1ull << (ffs64(start) - 1);
+		start_align = 1ull << (__ffs64(start) - 1);
 	law_sz = min(start_align, sz);
 	law_sz_enc = __ilog2_u64(law_sz) - 1;
 
@@ -202,7 +203,7 @@
 	if (sz) {
 		start += law_sz;
 
-		start_align = 1ull << (ffs64(start) - 1);
+		start_align = 1ull << (__ffs64(start) - 1);
 		law_sz = min(start_align, sz);
 		law_sz_enc = __ilog2_u64(law_sz) - 1;