arm64: dts: rockchip: add gpio-line-names to rk3328-rock-pi-e

Add names to the pins of the general-purpose expansion header as given
in the Radxa GPIO page[1] following the conventions in the kernel
documentation[2] to make it easier for users to correlate the pins with
functions when using utilities such as 'gpioinfo'.

Signed-off-by: Trevor Woerner <twoerner@gmail.com>
Link: https://lore.kernel.org/r/20231213160556.14424-1-twoerner@gmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>