patches: pharos: Drop patches merged upstream

patches: pharos: Drop patches merged upstream

Also, remove redundant pharos patch that adds prx mgmt IPs:
- "Re-assign mgmt network to proxy nodes"
as those values are set already (to different values!) by patch:
+ "extend public gateway support"

While at it, `make patches-export` should clean the patch dir first.

Change-Id: Ice106e5d48c7b4cd90ffc6af7441199034d4f546
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
(cherry picked from commit fbea9fae7a16f1375f7413ccd46146b015fc87ff)