clk: bcm: rpi: Handle pixel clock in firmware

clk: bcm: rpi: Handle pixel clock in firmware

The clk-bcm2835 handling of the pixel clock does not function
correctly when the HDMI power domain is disabled.

The firmware supports it correctly, so add it to the
firmware clock driver.

Acked-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Ivan T. Ivanov <iivanov@suse.de>
Link: https://lore.kernel.org/r/20220829152154.147250-3-iivanov@suse.de
Signed-off-by: Stephen Boyd <sboyd@kernel.org>