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-pxa/pxa95x.c b/arch/arm/mach-pxa/pxa95x.c
index 0961093..d082a58 100644
--- a/arch/arm/mach-pxa/pxa95x.c
+++ b/arch/arm/mach-pxa/pxa95x.c
@@ -211,6 +211,7 @@
 static DEFINE_PXA3_CKEN(pxa95x_ssp4, SSP4, 13000000, 0);
 static DEFINE_PXA3_CKEN(pxa95x_pwm0, PWM0, 13000000, 0);
 static DEFINE_PXA3_CKEN(pxa95x_pwm1, PWM1, 13000000, 0);
+static DEFINE_PXA3_CKEN(pxa95x_gpio, GPIO, 13000000, 0);
 
 static struct clk_lookup pxa95x_clkregs[] = {
 	INIT_CLKREG(&clk_pxa95x_pout, NULL, "CLK_POUT"),
@@ -229,6 +230,7 @@
 	INIT_CLKREG(&clk_pxa95x_ssp4, "pxa27x-ssp.3", NULL),
 	INIT_CLKREG(&clk_pxa95x_pwm0, "pxa27x-pwm.0", NULL),
 	INIT_CLKREG(&clk_pxa95x_pwm1, "pxa27x-pwm.1", NULL),
+	INIT_CLKREG(&clk_pxa95x_gpio, "pxa-gpio", NULL),
 };
 
 void __init pxa95x_init_irq(void)