arm64: dts: rockchip: Move RK3399 eDP pinctrl to boards

arm64: dts: rockchip: Move RK3399 eDP pinctrl to boards

The EDP_HOTPLUG pin is optional, and muxed with other functions (notably
HDMI CEC), so move its selection from the SoC DTSI to the boards which
apparently want it, namely those which enable eDP without "force-hpd".
By the same token we drop it from Pinebook Pro, which already uses
"force-hpd", and according to the schematics does not have the pin wired
at all.

Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://patch.msgid.link/c7d972d07875241805db8659305b26bd694867d4.1769191673.git.robin.murphy@arm.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>