meta-openpower: Convert MACHINE_FEATURE openpower-pflash to openpower-ubi-fs

Since pflash is no longer used when openpower-ubi-fs is enabled and
the only use of the openpower-pflash feature was to enable a pflash
dependency in obmc-op-flasher, remove obmc-op-flasher when
openpower-ubi-fs is enabled (thus removing pflash from the machine).

Change-Id: Ia11d2b11ac201a139e1c4d014d539d346e0c2479
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/meta-quanta/meta-q71l/conf/machine/quanta-q71l.conf b/meta-quanta/meta-q71l/conf/machine/quanta-q71l.conf
index 9f2b25e..91bde4e 100644
--- a/meta-quanta/meta-q71l/conf/machine/quanta-q71l.conf
+++ b/meta-quanta/meta-q71l/conf/machine/quanta-q71l.conf
@@ -17,7 +17,6 @@
 #        obmc-phosphor-flash-mgmt \
 #        obmc-host-ipmi \
 #        obmc-host-ctl \
-#        openpower-pflash \
 #        obmc-host-state-mgmt \
 #        obmc-chassis-state-mgmt \
 #        obmc-bmc-state-mgmt \