drm/i915: Move abs_diff() to math.h

abs_diff() belongs to math.h.  Move it there.  This will allow others to
use it.

[[email protected]: add abs_diff() documentation]
  Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix comment, per Randy]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]> # tty/serial
Acked-by: Jani Nikula <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Andi Shyti <[email protected]>
Reviewed-by: Philipp Zabel <[email protected]> # gpu/ipu-v3
Cc: Alexey Dobriyan <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Imre Deak <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Randy Dunlap <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions