phosphor-ipmi-config: Refactor phosphor-ipmi-config provider

The phopshor-ipmi-config provider witherspoon-ipmi-config is removed to use the
default configuration files. cipher_list.json and dcmi_cap.json for the
witherspoon is the same as the default configuration file. dcmi_sensors.json,
dev_id.json and power_reading.json is specific to witherspoon. do_patch
populates the aux field in dev_id.json for witherspoon.

Change-Id: I8d5aa255cd27865135028661cc89913695fdcb5b
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
8 files changed