ARM: qemu-arm: Dynamically determine timer frequency

After commit 46fc679e ("arm: timer: get frequency for arch timer
armv7 in cp15 cntfrq") the ARM architected timer driver knows how to
determine the timer frequency at runtime by reading the CNTFRQ register,
so we don't need to hardcode the timer frequency anymore.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>

include/configs/qemu-arm.h

@@ -19,11 +19,9 @@
 #define CONFIG_SYS_LOAD_ADDR		(CONFIG_SYS_SDRAM_BASE + SZ_2M)
 #define CONFIG_SYS_MALLOC_LEN		SZ_16M
 
-/* QEMU implements a 62.5MHz architected timer */
-/* FIXME: can we rely on CNTFREQ instead of hardcoding this fact here? */
+/* For timer, QEMU emulates an ARMv7/ARMv8 architected timer */
 #define CONFIG_SYS_ARCH_TIMER
 #define CONFIG_SYS_HZ                       1000
-#define CONFIG_SYS_HZ_CLOCK                 62500000
 
 /* For block devices, QEMU emulates an ICH9 AHCI controller over PCI */
 #define CONFIG_SYS_SCSI_MAX_SCSI_ID 6