keymaps: fix for systemd

keymaps: fix for systemd

Only install 'keymap.sh' script if 'sysvinit' is in DISTRO_FEATURES.
This is because systemd internally provides a mechanism to implement
the functionality this script tries to implement. Please see
systemd-vconsole-setup.service for more details.

Also we set 'INHIBIT_UPDATERCD_BBCLASS' to "1" if 'sysvinit' is not
in DISTRO_FEATURES.

(From OE-Core rev: 5e0aa114241b956f61cf852e1f4ff41b576adff4)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>