mlxsw: pci: Increase PCI reset timeout for SN3800 systems

SN3800 Spectrum-2 based systems have gearboxes that need to be
initialized by the firmware during its initialization flow. In certain
cases, the firmware might need to flash these gearboxes, which is
currently a time-consuming process.

In newer firmware versions, the firmware will not signal to the driver
that it is ready until the gearboxes are flashed. Increase the PCI reset
timeout for these situations. In normal cases, the driver will need to
wait no longer than 5 seconds.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>