ARM: pxa: add clk support in gpio driver

Support clk in gpio driver. There's no gpio clock in PXA25x and PXA27x.
So use dummy clk instead. And move the gpio edge initialization into
gpio driver for arch-mmp.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
diff --git a/arch/arm/mach-mmp/mmp2.c b/arch/arm/mach-mmp/mmp2.c
index 1ed222d..617c60a 100644
--- a/arch/arm/mach-mmp/mmp2.c
+++ b/arch/arm/mach-mmp/mmp2.c
@@ -93,18 +93,9 @@
 	__raw_writel(data, mfpr_pmic);
 }
 
-static void __init mmp2_init_gpio(void)
-{
-	int i;
-
-	/* enable GPIO clock */
-	__raw_writel(APBC_APBCLK | APBC_FNCLK, APBC_MMP2_GPIO);
-}
-
 void __init mmp2_init_irq(void)
 {
 	mmp2_init_icu();
-	mmp2_init_gpio();
 }
 
 static void sdhc_clk_enable(struct clk *clk)
@@ -141,6 +132,7 @@
 static APBC_CLK(twsi4, MMP2_TWSI4, 0, 26000000);
 static APBC_CLK(twsi5, MMP2_TWSI5, 0, 26000000);
 static APBC_CLK(twsi6, MMP2_TWSI6, 0, 26000000);
+static APBC_CLK(gpio, MMP2_GPIO, 0, 26000000);
 
 static APMU_CLK(nand, NAND, 0xbf, 100000000);
 static APMU_CLK_OPS(sdh0, SDH0, 0x1b, 200000000, &sdhc_clk_ops);
@@ -160,6 +152,7 @@
 	INIT_CLKREG(&clk_twsi5, "pxa2xx-i2c.4", NULL),
 	INIT_CLKREG(&clk_twsi6, "pxa2xx-i2c.5", NULL),
 	INIT_CLKREG(&clk_nand, "pxa3xx-nand", NULL),
+	INIT_CLKREG(&clk_gpio, "pxa-gpio", NULL),
 	INIT_CLKREG(&clk_sdh0, "sdhci-pxav3.0", "PXA-SDHCLK"),
 	INIT_CLKREG(&clk_sdh1, "sdhci-pxav3.1", "PXA-SDHCLK"),
 	INIT_CLKREG(&clk_sdh2, "sdhci-pxav3.2", "PXA-SDHCLK"),