Staging: epl: remove INLINE mess

extern inline isn't the nicest and it doesn't really make sense.
So unwind all the INLINE defines and includes, if speed is _really_ an
issue later stuff can be put back in a sane manner.

Cc: Daniel Krueger <daniel.krueger@systec-electronic.com>
Cc: Ronald Sieber <Ronald.Sieber@systec-electronic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>