ARM: rename CONFIG_TIMER_CLK_FREQ to COUNTER_FREQUENCY

Many ARMv8 boards define a constant COUNTER_FREQUENCY to specify the
frequency of the ARM Generic Timer (aka. arch timer).
ARMv7 boards traditionally used CONFIG_TIMER_CLK_FREQ for the same
purpose. It seems useful to unify them.
Since there are less occurences of the latter version, lets convert all
users over to COUNTER_FREQUENCY.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
diff --git a/arch/arm/cpu/armv7/nonsec_virt.S b/arch/arm/cpu/armv7/nonsec_virt.S
index 95ce938..e39aba7 100644
--- a/arch/arm/cpu/armv7/nonsec_virt.S
+++ b/arch/arm/cpu/armv7/nonsec_virt.S
@@ -188,11 +188,11 @@
  * we do this here instead.
  * But first check if we have the generic timer.
  */
-#ifdef CONFIG_TIMER_CLK_FREQ
+#ifdef COUNTER_FREQUENCY
 	mrc	p15, 0, r0, c0, c1, 1		@ read ID_PFR1
 	and	r0, r0, #CPUID_ARM_GENTIMER_MASK	@ mask arch timer bits
 	cmp	r0, #(1 << CPUID_ARM_GENTIMER_SHIFT)
-	ldreq	r1, =CONFIG_TIMER_CLK_FREQ
+	ldreq	r1, =COUNTER_FREQUENCY
 	mcreq	p15, 0, r1, c14, c0, 0		@ write CNTFRQ
 #endif