xtensa: drop extraneous register load from initialize_mmu

Commit a9f2fc628e ("xtensa: cleanup MMU setup and kernel layout macros")
removed the use of a2 in the beginning of the initialize_mmu macro, but
left the register load that is no longer used. Remove it as well.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/include/asm/initialize_mmu.h

@@ -73,7 +73,7 @@
 	_j	2f
 
 	.align	4
-1:	movi	a2, 0x10000000
+1:
 
 #if CONFIG_KERNEL_LOAD_ADDRESS < 0x40000000ul
 #define TEMP_MAPPING_VADDR 0x40000000