ARM: dts: bcm2835-rpi: Use firmware clocks for display

We've experienced a number of issues around the cohabitation between the
"real" clock driver in Linux and the one backed by the firmware.

One solution around this is to follow what the RaspberryPi foundation
in its downstream clock, which is also what we've been doing on the
RaspberryPi4: to use the clocks exposed by the firmware.

Link: https://lore.kernel.org/linux-clk/20221021140505.kjmw5x4s6qhnrfif@houat/


Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221026-rpi-display-fw-clk-v1-2-5c29b7a3d8b0@cerno.tech


Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>