qm1d1b0004: fix a warning about an unused default_cfg var

As warned by gcc:

	drivers/media/tuners/qm1d1b0004.c:62:39: warning: 'default_cfg' defined but not used [-Wunused-const-variable=]
	 static const struct qm1d1b0004_config default_cfg = {
	                                       ^~~~~~~~~~~

This var is currently unused. So, comment it out.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>