meta-ibm: palmetto: new YAML dependency scheme

A prior patch added a new recipe palmetto-yaml-config to provide all the
YAML configuration for Palmetto systems.  This patch switches the layer
to that recipe by setting EXTRA_OECONF and DEPENDS as appropriate in the
required bbappends.

With this switch, a number of recipes and their provided YAML are now
dead metadata, so remove those.

Change-Id: Ieaa7037b2b5b796072490fee19a21aa4ce578289
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
9 files changed