microblaze: start.S: use stack space as scratch memory for endian offset

To simpify the code, use stack space as scratch memory for endian offset
calculation, rather than saving/restoring the first unused MB vector.

Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Link: https://lore.kernel.org/r/20211130163358.2531677-5-ovidiu.panait@windriver.com
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/microblaze/cpu/start.S b/arch/microblaze/cpu/start.S
index 463e0fe..a1c0610 100644
--- a/arch/microblaze/cpu/start.S
+++ b/arch/microblaze/cpu/start.S
@@ -125,10 +125,8 @@
 	 * 4b) BIG endian - r10 contains 0x0 because 0x2 offset is on addr 0x3
 	 */
 	addik	r6, r0, 0x2 /* BIG/LITTLE endian offset */
-	lwi	r7, r0, 0x28
-	swi	r6, r0, 0x28 /* used first unused MB vector */
-	lbui	r10, r0, 0x28 /* used first unused MB vector */
-	swi	r7, r0, 0x28
+	sw	r6, r1, r0
+	lbu	r10, r1, r0
 
 	/* add opcode instruction for 32bit jump - 2 instruction imm & brai */
 	addi	r2, r0, 0xb0000000	/* hex b000 opcode imm */