ARM: OMAP1: ams-delta: Drop board specific global GPIO numbers

As all users of the board specific GPIO pins have been converted from
legacy integer-based to descriptor-based interface, there is no longer
a need to maintain statically assigned GPIO pin numbers.  Drop support
for that.

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>