reset: oxnas: replace file name with short description

Fixes a checkpatch warning:

  WARNING: It's generally not useful to have the filename in the file
  #3: FILE: drivers/reset/reset-oxnas.c:3:
  + * drivers/reset/reset-oxnas.c

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>