Create files with prototypes and static inlines for braille support. Make
braille_console functions return 1 on success.

Corrected CONFIG_A11Y_BRAILLE_CONSOLE=n _braille_console_setup
return value to NULL.

Signed-off-by: Joe Perches
Reviewed-by: Samuel Thibault
Cc: Ming Lei
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds