clk: bcm: rpi: Add disp clock

BCM2712 has an extra clock exposed by the firmware called DISP, and used
by (at least) the HVS. Let's add it to the list of clocks to register in
Linux.

Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20250116-bcm2712-clk-updates-v1-5-10bc92ffbf41@raspberrypi.com


Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>