board/sbc8548/sbc8548.c: Fix GCC 4.6 build warning

Fix:

sbc8548.c: In function 'local_bus_init':
sbc8548.c:80:7: warning: variable 'lbc_hz' set but not used [-Wunused-but-set-variable]

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/board/sbc8548/sbc8548.c b/board/sbc8548/sbc8548.c
index e1a3ea3..26095a5 100644
--- a/board/sbc8548/sbc8548.c
+++ b/board/sbc8548/sbc8548.c
@@ -77,12 +77,10 @@
 	volatile fsl_lbc_t *lbc = LBC_BASE_ADDR;
 
 	uint clkdiv;
-	uint lbc_hz;
 	sys_info_t sysinfo;
 
 	get_sys_info(&sysinfo);
 	clkdiv = (in_be32(&lbc->lcrr) & LCRR_CLKDIV) * 2;
-	lbc_hz = sysinfo.freqSystemBus / 1000000 / clkdiv;
 
 	out_be32(&gur->lbiuiplldcr1, 0x00078080);
 	if (clkdiv == 16) {