[MIPS] Fix build breakage due to duplicate cpu_clock definition

commit e436d80085133858bf2613a630365e8a0459fd58
Author: Ingo Molnar <mingo@elte.hu>
Date:   Thu Jul 19 21:28:35 2007 +0200

    [PATCH] sched: implement cpu_clock(cpu) high-speed time source

broke the build of several MIPS platforms which were already using the
symbol cpu_clock for the own purposes.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/pmc-sierra/yosemite/setup.c b/arch/mips/pmc-sierra/yosemite/setup.c
index f7f93ae..58862c8 100644
--- a/arch/mips/pmc-sierra/yosemite/setup.c
+++ b/arch/mips/pmc-sierra/yosemite/setup.c
@@ -59,7 +59,7 @@
 	0x00, 0xe0, 0x04, 0x00, 0x00, 0x21
 };
 
-unsigned long cpu_clock;
+unsigned long cpu_clock_freq;
 unsigned long yosemite_base;
 
 static struct m48t37_rtc *m48t37_base;
@@ -140,7 +140,7 @@
 
 void yosemite_time_init(void)
 {
-	mips_hpt_frequency = cpu_clock / 2;
+	mips_hpt_frequency = cpu_clock_freq / 2;
 mips_hpt_frequency = 33000000 * 3 * 5;
 }