media: cec: don't select PCI & DMI

While select would be a great idea for most archs, this
causes a breakage with s390:

	"I don't think that's a good idea, as it suddenly enables selecting all PCI
	 drivers on platforms that do not have PCI.

	    WARNING: unmet direct dependencies detected for PCI
	      Depends on [n]: HAVE_PCI [=n]
	      Selected by [m]:
	      - CEC_SECO [=m] && MEDIA_CEC_SUPPORT [=y] && (X86 || IA64 || COMPILE_TEST [=y])

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>