avr32: Move cpu_hz to arch_global_data

Move this field into arch_global_data and tidy up.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/avr32/cpu/cpu.c b/arch/avr32/cpu/cpu.c
index 7907837..9d82ca4 100644
--- a/arch/avr32/cpu/cpu.c
+++ b/arch/avr32/cpu/cpu.c
@@ -47,7 +47,7 @@
 {
 	extern void _evba(void);
 
-	gd->cpu_hz = CONFIG_SYS_OSC0_HZ;
+	gd->arch.cpu_hz = CONFIG_SYS_OSC0_HZ;
 
 	/* TODO: Move somewhere else, but needs to be run before we
 	 * increase the clock frequency. */
@@ -59,7 +59,7 @@
 	clk_init();
 
 	/* Update the CPU speed according to the PLL configuration */
-	gd->cpu_hz = get_cpu_clk_rate();
+	gd->arch.cpu_hz = get_cpu_clk_rate();
 
 	/* Set up the exception handler table and enable exceptions */
 	sysreg_write(EVBA, (unsigned long)&_evba);