MIPS: JZ4740: Add clocksource/clockevent support.

Add clocksource and clockevent support for the timer/counter unit on
JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1397/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>