drm/i915: Check for nomodeset in i915_init() first

When modesetting (aka the full pci driver, which has nothing to do
with disable_display option, which just gives you the full pci driver
without the display driver) is disabled, we load nothing and do
nothing.

So move that check first, for a bit of orderliness. With Jason's
module init/exit table this now becomes trivial.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727121037.2041102-1-daniel.vetter@ffwll.ch