ARM: dts: aspeed: Fix AST2600 machines line names

ARM: dts: aspeed: Fix AST2600 machines line names

Tacoma and Rainier both have a line-names array that is too long:

 gpio gpiochip0: gpio-line-names is length 232 but should be at most length 208

This was probably copied from an AST2500 device tree that did have more
GPIOs on the controller.

Fixes: e9b24b55ca4f ("ARM: dts: aspeed: rainier: Add gpio line names")
Fixes: 2f68e4e7df67 ("ARM: dts: aspeed: tacoma: Add gpio line names")
Link: https://lore.kernel.org/r/20210624090742.56640-1-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>