[media] DocBook: add entry IDs for enum fe_status
[media] DocBook: add entry IDs for enum fe_status

enum fe_status is documented together with FE_READ_STATUS.

Add xrefs for each entry there. This makes the hyperlinks at
frontend.h to go directly to the right documentation.

Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@osg.samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs