powerpc: mpc8xx: make get_immr() independent of CONFIG_8xx

SPRN_IMMR is defined regardless of the CPU. Therefore, there
is no point in enclosing get_immr() inside a #ifdef CONFIG_8xx

As it a static inline function, it will in any case only be
compiled in functons using it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

arch/powerpc/include/asm/ppc.h

@@ -40,14 +40,13 @@
 
 #include <asm/processor.h>
 
-#if defined(CONFIG_8xx)
 static inline uint get_immr(uint mask)
 {
 	uint immr = mfspr(SPRN_IMMR);
 
 	return mask ? (immr & mask) : immr;
 }
-#endif
+
 static inline uint get_pvr(void)
 {
 	return mfspr(PVR);