meta-openpower: Revert "host-fw: New recipe to include the host firmware"

This reverts commit d552bf6e0cf9cc1c9d4bfd650cf2765277cda980.

This host-fw recipe has been replaced by the phosphor-hostfw-image
recipe in the meta-phosphor layer. Delete it.

(From meta-openpower rev: 63a158cb84f01fa3462ebb8600e0362cdc5155f6)

Change-Id: I5d57b67a8b9f52b3c25c4a9c5d396c871c564de8
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>