V4L/DVB (8562): DVB_DRX397XD: remove FW_LOADER select

Also for the new DVB_DRX397XD driver the FW_LOADER select and the
corresponding dependency on HOTPLUG can be removed.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>