ar71xx: ag71xx: fix section mismatch warnings

ar71xx: ag71xx: fix section mismatch warnings

The function __devinit ag71xx_probe() references
a function __devexit ag71xx_phy_disconnect().
This is often seen when error handling in the init function
uses functionality in the exit path.
The fix is often to remove the __devexit annotation of
ag71xx_phy_disconnect() so it may be used outside an exit section.

The function ag71xx_phy_disconnect() references a function in an exit
section.
Often the function ag71xx_ar7240_cleanup() has valid usage outside the
exit section
and the fix is to remove the __devexit annotation of
ag71xx_ar7240_cleanup.

SVN-Revision: 26855