ARM: dts: aspeed: amd-ethanolx: Add GPIO line names

Add GPIO line names for AMD EthanolX customer reference board.
It populates AST2500 GPIO lines (A0-A7 to AC0-AC7) with AMD EthanolX
designated names.

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Reviewed-by: Supreeth Venkatesh <supreeth.venkatesh@amd.com>
Link: https://lore.kernel.org/r/20201111132133.1253-1-aladyshev22@gmail.com


Signed-off-by: Joel Stanley <joel@jms.id.au>