drm/i915: Implement workaround for CDCLK PLL disable/enable

drm/i915: Implement workaround for CDCLK PLL disable/enable

It was reported that we might get a hung and loss of register access in
some cases when CDCLK PLL is disabled and then enabled, while squashing
is enabled.
As a workaround it was proposed by HW team that SW should disable squashing
when CDCLK PLL is being reenabled.

v2: - Added WA number comment(Rodrigo Vivi)

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230130135836.12738-1-stanislav.lisovskiy@intel.com