meta-agl-profile-graphical: disable memfd usage in weston

meta-agl-profile-graphical: disable memfd usage in weston

The YP dunfell release's Weston 8.0.0 is the first version to switch
to hard-coded usage of memfd's for its shared memory access if the
memfd_create system call is available in libc. At the moment, this
is problematic since accesses to the non-filesystem file descriptors
get blocked by SMACK. For now, while a longer-term solution is
worked out in SPEC-3305, patch Weston to allow disabling memfs usage
at build time, and do so by using the option in our bbappend.

Bug-AGL: SPEC-3302, SPEC-3305

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: Ie217c63cd4f43e3de1e802cb026c1ee2905bc5b7