dt-bindings: clock: meson: a1: peripherals: support sys_pll input

The 'sys_pll' input is an optional clock that can be used to generate
'sys_pll_div16', which serves as one of the sources for the GEN clock.

Signed-off-by: Dmitry Rokosov <ddrokosov@salutedevices.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240515185103.20256-5-ddrokosov@salutedevices.com


Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>