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.

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@26855 3c298f89-4303-0410-b956-a3cf2f4a3e73