clk: mediatek: Disable tuner_en before change PLL rate

PLLs with tuner_en bit, such as APLL1, need to disable
tuner_en before apply new frequency settings, or the new frequency
settings (pcw) will not be applied.
The tuner_en bit will be disabled during changing PLL rate
and be restored after new settings applied.

Fixes: e2f744a8 (clk: mediatek: Add MT2712 clock support)
Cc: <stable@vger.kernel.org>
Signed-off-by: Owen Chen <owen.chen@mediatek.com>
Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Reviewed-by: James Liao <jamesjj.liao@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>