dropbear: add xauth runtime recommends dependency on x11 DISTRO_FEATURE
Change enable-x11-forwarding PACKAGECONFIG to x11, while we can rely
directly on X11 DISTRO_FEATURE. Previously when enable-x11-forwarding was
used, the XAUTH_COMMAND failed due to missing xauth. So add xauth to
runtime recommends dependency and enable this behavior as default.
Signed-off-by: Andrej Valek <andrej.v@skyrain.eu> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>