[media] drxk_hard.h: Remove some alien comment markups

X-Patchwork-Delegate: mchehab@redhat.com
The comments markup language used on Kernel is defined at:
	Documentation/kernel-doc-nano-HOWTO.txt
Remove invalid markups from the header file.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>