drm/amd/display: fix spelling mistake: synatpics -> synaptics

There are quite a few spelling mistakes in various function names
and error messages. Fix these.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>