arm64: gic: Do gicv3 secure initialization based on EL level

Do gic cpu initialization based on EL level which u-boot enters.
U-Boot can't access EL3 regs when runs in EL2/EL1, etc.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/lib/gic_64.S

@@ -107,6 +107,8 @@ ENTRY(gic_init_secure_percpu)
 	mov	w11, #0x1		/* Enable SGI 0 */
 	str	w11, [x10, GICR_ISENABLERn]
 
+	switch_el x10, 3f, 2f, 1f
+3:
 	/* Initialize Cpu Interface */
 	mrs	x10, ICC_SRE_EL3
 	orr	x10, x10, #0xf		/* SRE & Disable IRQ/FIQ Bypass & */
@@ -114,19 +116,19 @@ ENTRY(gic_init_secure_percpu)
 	msr	ICC_SRE_EL3, x10
 	isb
 
-	mrs	x10, ICC_SRE_EL2
-	orr	x10, x10, #0xf		/* SRE & Disable IRQ/FIQ Bypass & */
-					/* Allow EL1 access to ICC_SRE_EL1 */
-	msr	ICC_SRE_EL2, x10
-	isb
-
 	mov	x10, #0x3		/* EnableGrp1NS | EnableGrp1S */
 	msr	ICC_IGRPEN1_EL3, x10
 	isb
 
 	msr	ICC_CTLR_EL3, xzr
 	isb
-
+2:
+	mrs	x10, ICC_SRE_EL2
+	orr	x10, x10, #0xf		/* SRE & Disable IRQ/FIQ Bypass & */
+					/* Allow EL1 access to ICC_SRE_EL1 */
+	msr	ICC_SRE_EL2, x10
+	isb
+1:
 	msr	ICC_CTLR_EL1, xzr	/* NonSecure ICC_CTLR_EL1 */
 	isb