Zebra: Fix ptm-enable config failure on internally created interfaces

Zebra: Fix ptm-enable config failure on internally created interfaces

Ticket: CM-15658
Reviewed By: CCR-6534
Testing Done: Unit

Issue: frr ptm-enable command not working for interfaces that have been created by frr as a place holder.

Root Cause: The ptm-enable on interface configuration was not getting stored when the interface was internally created by frr.

Fix: Store the ptm-enable configuration even if the interface is internally created.

Signed-off-by: Radhika Mahankali <radhika@cumulusnetworks.com>