drm/arm/hdlcd: Use drm_gem_cma_print_info()

There is a new core debugfs file that prints fb/gem info:
<debugfs>/dri/<n>/framebuffer

Use drm_gem_cma_print_info() to provide info to that output instead
of using drm_fb_cma_debugfs_show().

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107191348.17555-10-noralf@tronnes.org