msm: emac: fix the lockup issue in SGMII ISR

Fix the lockup issue in SGMII ISR caused by the failure of interrupt status
clearing. When it happens, reset the SGMII PHY and MAC to recover.

Change-Id: I6fc586022fe85e0d247dc886e4f2d6524c5e7046
Acked-by: Jie Luo <jluo@qti.qualcomm.com>
Signed-off-by: Niranjana Vishwanathapura <nvishwan@codeaurora.org>