ARM: pxa: add dummy clock for pxa25x and pxa27x

gpio-pxa driver is shared among arch-pxa and arch-mmp. Clock is the
essential component on pxa3xx/pxa95x and arch-mmp. So we need to
define dummy clock in pxa25x/pxa27x instead.
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>

arch/arm/mach-pxa/pxa25x.c

@@ -209,6 +209,7 @@ static struct clk_lookup pxa25x_clkregs[] = {
 	INIT_CLKREG(&clk_pxa25x_gpio11, NULL, "GPIO11_CLK"),
 	INIT_CLKREG(&clk_pxa25x_gpio12, NULL, "GPIO12_CLK"),
 	INIT_CLKREG(&clk_pxa25x_mem, "pxa2xx-pcmcia", NULL),
+	INIT_CLKREG(&clk_dummy, "pxa-gpio", NULL),
 };
 
 static struct clk_lookup pxa25x_hwuart_clkreg =

arch/arm/mach-pxa/pxa27x.c

@@ -230,6 +230,7 @@ static struct clk_lookup pxa27x_clkregs[] = {
 	INIT_CLKREG(&clk_pxa27x_im, NULL, "IMCLK"),
 	INIT_CLKREG(&clk_pxa27x_memc, NULL, "MEMCLK"),
 	INIT_CLKREG(&clk_pxa27x_mem, "pxa2xx-pcmcia", NULL),
+	INIT_CLKREG(&clk_dummy, "pxa-gpio", NULL),
 };
 
 #ifdef CONFIG_PM