V4L/DVB (13951): rj54n1cb0: Storage class should be before const qualifier

The C99 specification states in section 6.11.5:

The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.

Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>