drm: Remove unused code to load the non-existing fbcon.ko

Commit 6104c370 ("fbcon: Make fbcon a built-time depency for fbdev")
changed the FRAMEBUFFER_CONSOLE Kconfig symbol from tristate to bool.

But the drm_kms_helper_init() function still attempts to load the fbcon
module, even when this is always built-in since the mentioned change.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210818120948.451896-1-javierm@redhat.com