connman-conf: don't take over any ethernet devices, not just eth0

connman-conf: don't take over any ethernet devices, not just eth0

The goal of connman-conf in qemu environments is to stop connman from
trying to control the network device, because runqemu will set it up
appropriately.

It currently hardcodes eth0, but 6.2 kernels onwards will rename eth0 to
en* even when the interface is already up[1]. So that this recipe
continues to work as intended, expand the list to "eth,en" so that
connman ignores _all_ ethernet devices with either the new or old names.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit?id=bd039b5ea2a91ea707ee8539df26456bd5be80af

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>