clk: at91: allow setting PMC_AUDIOPINCK clock parents via DT

Make AUDIOPINCK accessible via phandle to select it
as peripheral clock parent using assigned-clock-parents in DT
where available.

Signed-off-by: Zixun LI <admin@hifiphile.com>
Reviewed-by: Claudiu Beznea <Claudiu.Beznea@microchip.com>
Link: https://lore.kernel.org/r/20220111142051.37957-1-admin@hifiphile.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>