powerpc/mm/hash: Rename KERNEL_REGION_ID to LINEAR_MAP_REGION_ID

The region actually point to linear map. Rename the #define to
clarify thati.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/cell/spu_base.c

@@ -224,7 +224,7 @@ static void __spu_kernel_slb(void *addr, struct copro_slb *slb)
 	unsigned long ea = (unsigned long)addr;
 	u64 llp;
 
-	if (get_region_id(ea) == KERNEL_REGION_ID)
+	if (get_region_id(ea) == LINEAR_MAP_REGION_ID)
 		llp = mmu_psize_defs[mmu_linear_psize].sllp;
 	else
 		llp = mmu_psize_defs[mmu_virtual_psize].sllp;