dt-bindings: clk: vc5: Add properties for configuring the SD/OE pin

These properties allow configuring the SD/OE pin as described in the
datasheet.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210809223813.3766204-1-sean.anderson@seco.com


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