dt-bindings: pinctrl: pincfg-node: permit bias-high-impedance with other bias properties

dt-bindings: pinctrl: pincfg-node: permit bias-high-impedance with other bias properties

It is possible that devices tristate buffers may set the buffer to
the high-Z state in addition to setting pull-up or pull-down on a pin.
Remove this particular restriction to prevent warning on zynqmp systems
where this configuration seems to be valid.

Reported-by: Rob Herring (Arm) <robh@kernel.org>
Fixes: a901e8705f89f ("dt-bindings: pinctrl: pincfg-node: add restrictions on conflicting properties")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>