Implement TMKNOD as part of 2000.L Work

Synopsis

    size[4] Tmknod tag[2] fid[4] name[s] mode[4] major[4] minor[4] gid[4]

    size[4] Rmknod tag[2] qid[13]

Description

    mknod asks the file server to create a device node with given device
    type, mode and gid. The qid for the new device node is returned with
    the mknod reply message.
Signed-off-by: NM. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>