clocksource/drivers/pistachio: Make it selectable for MIPS

So it will be avilable for generic MIPS kernel.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

drivers/clocksource/Kconfig

@@ -234,8 +234,9 @@ config CLKSRC_LPC32XX
 	  Support for the LPC32XX clocksource.
 
 config CLKSRC_PISTACHIO
-	bool "Clocksource for Pistachio SoC" if COMPILE_TEST
+	bool "Clocksource for Pistachio SoC"
 	depends on HAS_IOMEM
+	depends on MIPS || COMPILE_TEST
 	select TIMER_OF
 	help
 	  Enables the clocksource for the Pistachio SoC.