Armv8: Initializing CNTVOFF_EL2

Linux-arm64 require that CNTVOFF_EL2 should be programmed with
a consistent value on all cpus. Initializing CNTVOFF_EL2 at state
transition instead of start.S could prevent potential different value
on cpus if ATF exist and u-boot runs at only one cpu.
Signed-off-by: NDavid Feng <fenghua@phytium.com.cn>

arch/arm/include/asm/macro.h

@@ -143,6 +143,9 @@ lr	.req	x30
 	mov	\xreg1, #0x33ff
 	msr	cptr_el2, \xreg1	/* Disable coprocessor traps to EL2 */
 
+	/* Initialize Generic Timers */
+	msr	cntvoff_el2, xzr
+
 	/* Initialize SCTLR_EL2
 	 *
 	 * setting RES1 bits (29,28,23,22,18,16,11,5,4) to 1