Reading from /dev/r0Btn only allowed to read one button at a time. Reading GPIO
directly via ioctl() doesn't have this limitation.
This adds a more complete GPIO list also.
Change-Id: If47b0846472f0817305dbf930731255f875e0269
Author: Lorenzo Miori
move prototypes to ascodec.h
move code to ascodec*.c
YPR0: use adc-as3514.c instead of duplicating it
TODO: merge as3514.h and ascodec.h ?
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31626 a1c6a512-1295-4272-9138-f99709370657