meta-ibm: remove phosphor-isolation from witherspoon and romulus

The distro feature phosphor-isolation is added into openbmc-openpower
distro feature and becomes common for all openpower machines.
So remove them from meta-witherspoon and meta-romulus.

This shall be merged after the commit of adding phosphor-isolation in
openbmc-openpower is merged.

Tested: Verify the Romulus build picks phosphor-isolation distro feature

Change-Id: I7cb8152a41b9e3f6ed40633599a4e79c6efcb306
Signed-off-by: Lei YU <mine260309@gmail.com>
2 files changed