smb3: update protocol header definitions based to include new flags

[MS-SMB2] protocol specification was recently updated to include
new flags, new negotiate context and some minor changes to fields.
Update smb2pdu.h structure definitions to match the newest version
of the protocol specification.  Updates to the compression context
values will be in a followon patch.

Signed-off-by: Steve French <stfrench@microsoft.com>