MIPS: Malta: remove unused cpu_khz variable

This variable was introduced by commit 96348c8f (of Ralf's historic
Linux/MIPS repository) "Remaining fixes for MIPS's eval boards." but
I don't see any use of it either then or now. Remove it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6171/

arch/mips/mti-malta/malta-time.c

@@ -42,8 +42,6 @@
 #include <asm/mips-boards/generic.h>
 #include <asm/mips-boards/maltaint.h>
 
-unsigned long cpu_khz;
-
 static int mips_cpu_timer_irq;
 static int mips_cpu_perf_irq;
 extern int cp0_perfcount_irq;
@@ -182,7 +180,6 @@ void __init plat_time_init(void)
 	freq = freqround(freq, 5000);
 	printk("CPU frequency %d.%02d MHz\n", freq/1000000,
 	       (freq%1000000)*100/1000000);
-	cpu_khz = freq / 1000;
 
 	mips_scroll_message();