obmc-phosphor-image: Don't install any locales

Don't install any locales in an obmc-phosphor-image.  The defaults
probably meet most requirements at present and this saves ~128K with an
xz compressed squashfs.

Remove locale setting from distro configuration.  The defaults are fine
and this also allows the user to override.

(From meta-phosphor rev: c2207adeb8ecfa1add3868eafc1f0d94d2e503d7)

Change-Id: I2bd5eb4225cfd8f0024b14afc415c0c1bd166484
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>