i.MX51: Use correct clock for gpt

The gpt uses the ipg clock, not ipg_perclk

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx5/clock-mx51.c b/arch/arm/mach-mx5/clock-mx51.c
index be90c03..8f85f73 100644
--- a/arch/arm/mach-mx5/clock-mx51.c
+++ b/arch/arm/mach-mx5/clock-mx51.c
@@ -757,7 +757,7 @@
 
 /* GPT */
 DEFINE_CLOCK(gpt_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG9_OFFSET,
-	NULL,  NULL, &ipg_perclk, NULL);
+	NULL,  NULL, &ipg_clk, NULL);
 DEFINE_CLOCK(gpt_ipg_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG10_OFFSET,
 	NULL,  NULL, &ipg_clk, NULL);