agl-weston-waltham-remoting: Add waltham-remoting AGL_FEATURES

agl-weston-waltham-remoting: Add waltham-remoting AGL_FEATURES

Like weston-remoting DISTRO FEATURES this allows us to control when to
build the transmitter-plugin and to add a suitable weston.ini
'transmitter-section' which will be added following this patch.

Bug-AGL: SPEC-3601

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: I2b54fac62ad7bee3e647d0b6e0162c7ad1aff1bd
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/25453
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-boot-test: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>