drm: use .hword to represent 16-bit numbers

The size of .word is the size of a word in the given platform, which
for intel systems is 16-bits but other architectures use different
sizes.  However, .hword emits 16-bit numbers regardless of the
platform (and despite the name).  The quantities specified in EDID are
platform independent, so they should work in spite of the default
target of the cc you are using, so use .hword where EDID specifies
16-bit numbers.

Cc: Carsten Emde <C.Emde@osadl.org>
Cc: David Airlie <airlied@linux.ie>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Javi Merino <javi.merino@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1490795123-16851-1-git-send-email-javi.merino@kernel.org