drm/vkms: enable cursor by default

This patch proposes a change in the behavior of the cursor to enable it as
soon as the vkms module is added. Enabling the cursor by default appears
to be an expected and more friendly behavior, especially when running IGT
tests.

Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200321203740.pg3r7f4vybruowox@smtp.gmail.com