ARM: dts: msm: Update EMAC phy interrupt for sdxpoorwills

GPIO84 is connected to PHY interrupt pin.
Update name for GPIO84 interrupt as phy-intr.
This pin handles PHY events like link-up/link-down/wake-on-LAN.

Change-Id: I79ad9c1eddfbc5dbb19724aed0d4c6e373a91fa7
CRs-Fixed: 2223746
Acked-by: Rahul Kawadgave <rahulak@qti.qualcomm.com>
Signed-off-by: Sunil Paidimarri <hisunil@codeaurora.org>