drm/bridge: cdns-dsi: Fix issue with phy init

Phy is not being initialized after suspend resume. Fix this by setting
phy_initialized flag to false in suspend callback

Upstream Link: https://lore.kernel.org/all/20221115083918.23192-1-r-ravikumar@ti.com/



Signed-off-by: Rahul T R <r-ravikumar@ti.com>