ARM: pxa: add rtc dummy clock

sa1100-rtc driver could be shared among sa1100/pxa/mmp series silicon.
Since clk is used in mmp series silicon, add dummy clock support in
pxa also.

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 d082a58..35023d7 100644
--- a/arch/arm/mach-pxa/pxa95x.c
+++ b/arch/arm/mach-pxa/pxa95x.c
@@ -231,6 +231,7 @@
 	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),
+	INIT_CLKREG(&clk_dummy, "sa1100-rtc", NULL),
 };
 
 void __init pxa95x_init_irq(void)