arm/errata: Update required bits for A57 cores erratas

This patch updates the setting of required bits for A57 cores erratas
- 828024 and 826974

Signed-off-by: Bhupesh Sharma <bhupesh.sharma at freescale.com>
Signed-off-by: Dai Haruki <dai.haruki at freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar at freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

arch/arm/cpu/armv8/start.S

@@ -115,18 +115,18 @@ apply_a57_core_errata:
 #ifdef CONFIG_ARM_ERRATA_828024
 	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
 	/* Disable non-allocate hint of w-b-n-a memory type */
-	mov	x0, #0x1 << 49
+	orr	x0, x0, #1 << 49
 	/* Disable write streaming no L1-allocate threshold */
-	mov	x0, #0x3 << 25
+	orr	x0, x0, #3 << 25
 	/* Disable write streaming no-allocate threshold */
-	mov	x0, #0x3 << 27
+	orr	x0, x0, #3 << 27
 	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
 #endif
 
 #ifdef CONFIG_ARM_ERRATA_826974
 	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
 	/* Disable speculative load execution ahead of a DMB */
-	mov	x0, #0x1 << 59
+	orr	x0, x0, #1 << 59
 	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
 #endif