When a slave-output is rotated the transformation is done on the blit
from master to slave GPU, so crtc->transform_in_use is not set, but we
still need to adjust the mouse position for things to work.

This commit modifies xf86_crtc_transform_cursor_position to not rely
on crtc->f_framebuffer_to_crtc, so that it can be used with GPU screens
too and always calls it for crtcs with any form of rotation.

Note not using crtc->f_framebuffer_to_crtc means that crtc->transform
will not be taken into account, that is ok, because when we've a transform
active hw-cursors are not used and xf86_crtc_transform_cursor_position
will never get called.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-and-Tested-by: Michel Dänzer <michel.daenzer@amd.com>