powerpc, 8xx: move get_immr() into C

Avoid unnecessary assembly functions when they can easily be written
in C.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>

arch/powerpc/cpu/mpc8xx/start.S

@@ -305,21 +305,6 @@ int_return:
 	SYNC
 	rfi
 
-/*
- * unsigned int get_immr (unsigned int mask)
- *
- * return (mask ? (IMMR & mask) : IMMR);
- */
-	.globl	get_immr
-get_immr:
-	mr	r4,r3		/* save mask */
-	mfspr	r3, IMMR	/* IMMR */
-	cmpwi	0,r4,0		/* mask != 0 ? */
-	beq	4f
-	and	r3,r3,r4	/* IMMR & mask */
-4:
-	blr
-
 	.globl get_pvr
 get_pvr:
 	mfspr	r3, PVR

arch/powerpc/include/asm/ppc.h

@@ -38,8 +38,15 @@
 #include <asm/arch/immap_lsch2.h>
 #endif
 
+#include <asm/processor.h>
+
 #if defined(CONFIG_8xx)
-uint get_immr(uint);
+static inline uint get_immr(uint mask)
+{
+	uint immr = mfspr(SPRN_IMMR);
+
+	return mask ? (immr & mask) : immr;
+}
 #endif
 uint get_pvr(void);
 uint get_svr(void);