Merge branch 'mlxsw-use-MRSR-register-for-FW-reset'

Ido Schimmel says:

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mlxsw: use MRSR register for FW reset

Jiri says:

Introduce a MRSR register definition and use it to do FW reset instead
of existing mechanism using PCI BAR0 register.
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Signed-off-by: David S. Miller <davem@davemloft.net>