[ARM] pxa: introduce reset_status and clear_reset_status for driver's usage

Due to the problem of reset status bits being handled by different
registers between pxa2xx and pxa3xx, introduce a global reset_status
variable, initialized by SoC-specific code and later being used by
other drivers.

And also introduce clear_reset_status(), which is used to clear the
corresponding status bits. Pass RESET_STATUS_ALL to clear all bits.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
diff --git a/arch/arm/mach-pxa/generic.h b/arch/arm/mach-pxa/generic.h
index 5bb7ae7..041c04832 100644
--- a/arch/arm/mach-pxa/generic.h
+++ b/arch/arm/mach-pxa/generic.h
@@ -47,12 +47,20 @@
 #define pxa27x_get_memclk_frequency_10khz()	(0)
 #endif
 
+#if defined(CONFIG_PXA25x) || defined(CONFIG_PXA27x)
+extern void pxa2xx_clear_reset_status(unsigned int);
+#else
+static inline void pxa2xx_clear_reset_status(unsigned int mask) {}
+#endif
+
 #ifdef CONFIG_PXA3xx
 extern unsigned pxa3xx_get_clk_frequency_khz(int);
 extern unsigned pxa3xx_get_memclk_frequency_10khz(void);
+extern void pxa3xx_clear_reset_status(unsigned int);
 #else
 #define pxa3xx_get_clk_frequency_khz(x)		(0)
 #define pxa3xx_get_memclk_frequency_10khz()	(0)
+static inline void pxa3xx_clear_reset_status(unsigned int mask) {}
 #endif
 
 extern struct sysdev_class pxa_irq_sysclass;