[ARM] 4526/1: pxa: make ARCH_PXA select GENERIC_CLOCKEVENTS

make ARCH_PXA select GENERIC_CLOCKEVENTS to fix the
building issue due to merge of clockevents based PXA
timer
Signed-off-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig

@@ -341,6 +341,7 @@ config ARCH_PXA
 	select ARCH_MTD_XIP
 	select GENERIC_GPIO
 	select GENERIC_TIME
+	select GENERIC_CLOCKEVENTS
 	help
 	  Support for Intel's PXA2XX processor line.