ARC: fix new Section mismatches in build (post __cpuinit cleanup)

```------------>8--------------------
WARNING: vmlinux.o(.text+0x708): Section mismatch in reference from the
function read_arc_build_cfg_regs() to the function
.init.text:read_decode_cache_bcr()

WARNING: vmlinux.o(.text+0x702): Section mismatch in reference from the
function read_arc_build_cfg_regs() to the function
.init.text:read_decode_mmu_bcr()
```

------------>8--------------------
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/cache.h

@@ -57,7 +57,7 @@
 
 extern void arc_cache_init(void);
 extern char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len);
-extern void __init read_decode_cache_bcr(void);
+extern void read_decode_cache_bcr(void);
 
 #endif	/* !__ASSEMBLY__ */
 

arch/arc/include/asm/mmu.h

@@ -59,7 +59,7 @@ void tlb_paranoid_check(unsigned int mm_asid, unsigned long address);
 
 void arc_mmu_init(void);
 extern char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len);
-void __init read_decode_mmu_bcr(void);
+void read_decode_mmu_bcr(void);
 
 #endif	/* !__ASSEMBLY__ */