meson: Remove freerdp1 as it no longer builds

../libweston/compositor-rdp.c: In function ‘rdp_peer_refresh_rfx’:
../libweston/compositor-rdp.c:213:25: error: invalid type argument of unary ‘*’ (have ‘SURFACE_BITS_COMMAND’ {aka ‘struct _SURFACE_BITS_COMMAND’})
  memset(&cmd, 0, sizeof(*cmd));

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>