drm/i915: Make hdcp2_msg_timeout.timeout u16

drm/i915: Make hdcp2_msg_timeout.timeout u16

All the timeout values fit in u16, so let's shrink the structure
a bit.

This ends up actually increasing the .text size a bit due to
some changes in instructions (constant imul+small jmps replaced
with mov+bigger jmpqs). Seems pretty arbitrary to me so I'll
just pretend I didn't see it.

    text	   data	    bss	    dec	    hex	filename
-  34521	    360	      0	  34881	   8841	intel_hdmi.o
+  34537	    360	      0	  34897	   8851	intel_hdmi.o

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191010145127.7487-5-ville.syrjala@linux.intel.com
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>