mlxsw: pci: Wait after reset before accessing HW

[ Upstream commit 8e033a93b37f37aa9fca71a370a895155320af60 ]

After performing reset driver polls on HW indication until learning
that the reset is done, but immediately after reset the device becomes
unresponsive which might lead to completion timeout on the first read.

Wait for 100ms before starting the polling.

Fixes: 233fa44b ("mlxsw: pci: Implement reset done check")
Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>