net: phy: phylink: fix uninitialized variable in phylink_get_mac_state

When debugging an issue I found implausible values in state->pause.
Reason in that state->pause isn't initialized and later only single
bits are changed. Also the struct itself isn't initialized in
phylink_resolve(). So better initialize state->pause and other
not yet initialized fields.

v2:
- use right function name in subject
v3:
- initialize additional fields

Fixes: 9525ae83 ("phylink: add phylink infrastructure")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>