9p: Implement LOPEN

Implement 9p2000.L version of open(LOPEN) interface in 9p client.

For LOPEN, no need to convert the flags to and from 9p mode to VFS mode.

Synopsis:

    size[4] Tlopen tag[2] fid[4] mode[4]

    size[4] Rlopen tag[2] qid[13] iounit[4]

[Fix mode bit format - jvrao@linux.vnet.ibm.com]

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbegren <ericvh@gmail.com>
diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 06d111d..cf580a4 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -139,6 +139,8 @@
 enum p9_msg_t {
 	P9_TSTATFS = 8,
 	P9_RSTATFS,
+	P9_TLOPEN = 12,
+	P9_RLOPEN,
 	P9_TLCREATE = 14,
 	P9_RLCREATE,
 	P9_TSYMLINK = 16,