ARM i.MX: remove now unnecessary argument from mxc_timer_init

As the timer code now does a clk_get to get its clock we don't
need the struct clk argument anymore.
This also changes the alternative EPIT timer to do a clk_get.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-imx/clk-imx21.c b/arch/arm/mach-imx/clk-imx21.c
index 4e4f384..ea13e61 100644
--- a/arch/arm/mach-imx/clk-imx21.c
+++ b/arch/arm/mach-imx/clk-imx21.c
@@ -180,7 +180,7 @@
 	clk_register_clkdev(clk[sdhc1_ipg_gate], "sdhc1", NULL);
 	clk_register_clkdev(clk[sdhc2_ipg_gate], "sdhc2", NULL);
 
-	mxc_timer_init(NULL, MX21_IO_ADDRESS(MX21_GPT1_BASE_ADDR),
-			MX21_INT_GPT1);
+	mxc_timer_init(MX21_IO_ADDRESS(MX21_GPT1_BASE_ADDR), MX21_INT_GPT1);
+
 	return 0;
 }