clk: sunxi: unify APB1 clock

This commit unifies the APB1 mux with the APB1 clock, using the new
factors infrastructure.

Signed-off-by: Emilio López <emilio@elopez.com.ar>
[wens@csie.org: Add mux mask bits]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
ARM: dts: sunxi: unify APB1 clock

With the new factors infrastructure in place, we can unify apb1 and
apb1_mux as a single clock now.

Signed-off-by: Emilio López <emilio@elopez.com.ar>
[wens@csie.org: Change apb1 node label to "apb1"; reword commit title]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
ARM: dts: sunxi: Use sun4i-a10-apb1-clk for sun6i/sun8i apb2 clocks.

The apb2 clocks are actually the same as apb1 clocks on the other sunxi
platforms, hence compatible with "allwinner,sun4i-a10-apb1-clk".

Update the dtsi to use the new unified apb1 clk.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
clk: sunxi: Removed unused/incorrect sun6i-a31-apb2-clk driver

This driver does not match the hardware, which is actually compatible
to sun4i-a10-apb1-clk. Since we've switch to the correct one, drop
this driver.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>