cxgb4: halt chip before flashing PHY firmware image

cxgb4: halt chip before flashing PHY firmware image

[ Upstream commit 6d297540f75d759489054e8b07932208fc4db2cb ]

When using firmware-assisted PHY firmware image write to flash,
halt the chip before beginning the flash write operation to allow
the running firmware to store the image persistently. Otherwise,
the running firmware will only store the PHY image in local on-chip
RAM, which will be lost after next reset.

Fixes: 4ee339e1e92a ("cxgb4: add support to flash PHY image")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>