Regular 8-bit and Deep Color video formats mainly differ in TMDS rate and
not in pixel clock rate.
When the hdmiphy clock is configured with the same pixel clock rate using
clk_set_rate() the clock framework do not signal the hdmi phy driver
to set_rate when switching between 8-bit and Deep Color.
This result in pre/post pll not being re-configured when switching between
regular 8-bit and Deep Color video formats.

Fix this by calling set_rate in power_on to force pre pll re-configuration.
Signed-off-by: Huicong Xu <xhc@rock-chips.com>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Link: https://lore.kernel.org/r/20230615171005.2251032-6-jonas@kwiboo.seSigned-off-by: Vinod Koul <vkoul@kernel.org>