net: dsa: mv88e6xxx: fix style issues

This patch fixes 5 style problems reported by checkpatch:

    WARNING: suspect code indent for conditional statements (8, 24)
    #492: FILE: drivers/net/dsa/mv88e6xxx.c:492:
    +	if (phydev->link)
    +			reg |= PORT_PCS_CTRL_LINK_UP;

    CHECK: Logical continuations should be on the previous line
    #1318: FILE: drivers/net/dsa/mv88e6xxx.c:1318:
    +		     oldstate == PORT_CONTROL_STATE_FORWARDING)
    +		    && (state == PORT_CONTROL_STATE_DISABLED ||

    CHECK: multiple assignments should be avoided
    #1662: FILE: drivers/net/dsa/mv88e6xxx.c:1662:
    +		vlan->vid_begin = vlan->vid_end = next.vid;

    WARNING: line over 80 characters
    #2097: FILE: drivers/net/dsa/mv88e6xxx.c:2097:
    +				       const struct switchdev_obj_port_vlan *vlan,

    WARNING: suspect code indent for conditional statements (16, 32)
    #2734: FILE: drivers/net/dsa/mv88e6xxx.c:2734:
    +		if (mv88e6xxx_6352_family(ps) || mv88e6xxx_6351_family(ps) ||
    [...]
    +				reg |= PORT_CONTROL_EGRESS_ADD_TAG;

    total: 0 errors, 3 warnings, 2 checks, 3805 lines checked

It also rebases and integrates changes sent by Ben Dooks [1]:

    The driver has a number of functions that are not exported or
    declared elsewhere, so make them static to avoid the following
    warnings from sparse:

    drivers/net/dsa/mv88e6xxx.c:113:5: warning: symbol 'mv88e6xxx_reg_read' was not declared. Should it be static?
    drivers/net/dsa/mv88e6xxx.c:167:5: warning: symbol 'mv88e6xxx_reg_write' was not declared. Should it be static?
    drivers/net/dsa/mv88e6xxx.c:231:5: warning: symbol 'mv88e6xxx_set_addr' was not declared. Should it be static?
    drivers/net/dsa/mv88e6xxx.c:367:6: warning: symbol 'mv88e6xxx_ppu_state_init' was not declared. Should it be static?
    drivers/net/dsa/mv88e6xxx.c:3157:5: warning: symbol 'mv88e6xxx_phy_page_read' was not declared. Should it be static?
    drivers/net/dsa/mv88e6xxx.c:3169:5: warning: symbol 'mv88e6xxx_phy_page_write' was not declared. Should it be static?
    drivers/net/dsa/mv88e6xxx.c:3583:26: warning: symbol 'mv88e6xxx_switch_driver' was not declared. Should it be static?
    drivers/net/dsa/mv88e6xxx.c:3621:5: warning: symbol 'mv88e6xxx_probe' was not declared. Should it be static?

[1] http://patchwork.ozlabs.org/patch/632708/

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>