drivers/clk: convert sunxi/clk-mod0.c to use builtin_platform_driver

This driver builds based on obj-y and hence will not ever be
modular.  Change it to use the non-modular registration so that it
won't suffer a compile fail once a header move places the modular
registration within the module.h file.

Cc: "Emilio López" <emilio@elopez.com.ar>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>