configs: set CONFIG_COUNTER_FREQUENCY

Set CONFIG_COUNTER_FREQUENCY according to COUNTER_FREQUENCY in
config header file.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
[trini: Re-run migration]
diff --git a/configs/vexpress_aemv8r_defconfig b/configs/vexpress_aemv8r_defconfig
index 612797e..a1c5d88 100644
--- a/configs/vexpress_aemv8r_defconfig
+++ b/configs/vexpress_aemv8r_defconfig
@@ -1,4 +1,5 @@
 CONFIG_ARM=y
+CONFIG_COUNTER_FREQUENCY=24000000
 CONFIG_ARCH_VEXPRESS64=y
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_DEFAULT_DEVICE_TREE="arm_fvp"