clocksource/drivers: Rename CLKSRC_OF to TIMER_OF

The config option name is now renamed to 'TIMER_OF' for consistency with
the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

arch/mips/ralink/Kconfig

@@ -4,7 +4,7 @@ config CLKEVT_RT3352
 	bool
 	depends on SOC_RT305X || SOC_MT7620
 	default y
-	select CLKSRC_OF
+	select TIMER_OF
 	select CLKSRC_MMIO
 
 config RALINK_ILL_ACC