compositor-drm: Fix cursor view size check
compositor-drm: Fix cursor view size check

Instead of testing against a hardcoded 64x64 pixel size to see if a view
is suitable for promotion to a cursor plane, use our cursor_width and
cursor_height variables.

Signed-off-by: Daniel Stone <62e7e355d5d8400fa8384448796af0bf6be4ffae@collabora.com>
Reviewed-by: Derek Foreman <2f97e0f0bc172406aab8ccd42dab54c95bab8759@osg.samsung.com>

xorgy/weston,krezovic/weston,eyolfson/weston,giucam/weston,jonnylamb/weston,udoprog/weston,kwm81/weston,sir-murray/weston,kwm81/weston,Fantu/compositor-spice,giucam/weston,Tarnyko/weston-xdg_surface_present,Tarnyko/weston-xdg_surface_present,sir-murray/weston,eyolfson/weston,krezovic/weston,Gnurou/weston,Gnurou/weston,xorgy/weston,Fantu/compositor-spice,jonnylamb/weston,Fantu/compositor-spice,udoprog/weston