clocksource/drivers/sun4i: Change name sun4i_timer to timer-sun4i

In order to unify the names in this directory, let's rename the driver to be
prefixed with timer-*
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/Makefile

@@ -32,7 +32,7 @@ obj-$(CONFIG_MXS_TIMER)		+= mxs_timer.o
 obj-$(CONFIG_CLKSRC_PXA)	+= pxa_timer.o
 obj-$(CONFIG_PRIMA2_TIMER)	+= timer-prima2.o
 obj-$(CONFIG_U300_TIMER)	+= timer-u300.o
-obj-$(CONFIG_SUN4I_TIMER)	+= sun4i_timer.o
+obj-$(CONFIG_SUN4I_TIMER)	+= timer-sun4i.o
 obj-$(CONFIG_SUN5I_HSTIMER)	+= timer-sun5i.o
 obj-$(CONFIG_MESON6_TIMER)	+= meson6_timer.o
 obj-$(CONFIG_TEGRA_TIMER)	+= timer-tegra20.o