move adc_close() prototype to adc.h
don't duplicate prototypes of adc.h
remove license header and guards for a single include of another file or for empty content
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31623 a1c6a512-1295-4272-9138-f99709370657
Included are drivers for buttons, backlight, lcd, audio and storage.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31000 a1c6a512-1295-4272-9138-f99709370657