drm/gem-fb-helper: Consistenly use drm_dbg_kms()

drm/gem-fb-helper: Consistenly use drm_dbg_kms()

All debug messages in drm_gem_framebuffer_helper.c use drm_dbg_kms(),
except for one, which uses drm_dbg().
Replace the outlier by drm_dbg_kms() to restore consistency.

Fixes: c91acda3a380 ("drm/gem: Check for valid formats")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7d56615fbef2d4d0e5f4c4a23f57269bf8bdb71f.1690535176.git.geert+renesas@glider.be