clk: meson: meson8b: fix the width of the cpu_scale_div clock

clk: meson: meson8b: fix the width of the cpu_scale_div clock

According to the public S805 datasheet HHI_SYS_CPU_CLK_CNTL1[29:20] is
the register for the CPU scale_div clock. This matches the code in
Amlogic's 3.10 GPL kernel sources:
N = (aml_read_reg32(P_HHI_SYS_CPU_CLK_CNTL1) >> 20) & 0x3FF;

This means that the divider register is 10 bit wide instead of 9 bits.
So far this is not a problem since all u-boot versions I have seen are
not using the cpu_scale_div clock at all (instead they are configuring
the CPU clock to run off cpu_in_sel directly).

The fixes tag points to the latest rework of the CPU clocks. However,
even before the rework it was wrong. Commit 7a29a869434e8b ("clk: meson:
Add support for Meson clock controller") defines MESON_N_WIDTH as 9 (in
drivers/clk/meson/clk-cpu.c). But since the old clk-cpu implementation
this only carries the fixes tag for the CPU clock rewordk.

Fixes: 251b6fd38bcb9c ("clk: meson: rework meson8b cpu clock")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20180927085921.24627-3-martin.blumenstingl@googlemail.com