net: ti: prueth_core: hsr/prp: add Multicast filtering

Similar to Dual EMAC firmware, HSR/PRP (LRE) firmware also
supports a hashed Multicast filter table of 256 entries.
This patch extends the MC filtering support to HSR/PRP Ethernet
types. This is a shared table for LRE. So protect access
using a spinlock.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>