V4L/DVB (7861): mt312: Prefix functions only with mt312_, Add zl10313 to kconfig description

This patch does some small cleanup to mt312.
It changes kconfig description to also list the ZL10313.

It does change some strange symbol names to be consistent with
module name mt312 and naming of all other functions in there.
* vp310_mt312_ops -> mt312_ops
* vp310_mt312_attach -> mt312_attach

Adds a MODULE_AUTHOR for me

Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>