net: stmmac: introduce MSI Interrupt routines for mac, safety, RX & TX

Now we introduce MSI interrupt service routines and hook these routines
up if stmmac_open() sees valid irq line being requested:-

stmmac_mac_interrupt()    :- MAC (dev->irq), WOL (wol_irq), LPI (lpi_irq)
stmmac_safety_interrupt() :- Safety Feat Correctible Error (sfty_ce_irq)
                             & Uncorrectible Error (sfty_ue_irq)
stmmac_msi_intr_rx()      :- For all RX MSI irq (rx_irq)
stmmac_msi_intr_tx()      :- For all TX MSI irq (tx_irq)

Each of IRQs will have its unique name so that we can differentiate
them easily under /proc/interrupts.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>