Merge branch 'add-phy-shared-storage'

Michael Walle says:

====================
add phy shared storage

Introduce the concept of a shared PHY storage which can be used by some
QSGMII PHYs to ease initialization and access to global per-package
registers.

Changes since v2:
 - restore page to standard after reading the base address in the mscc
   driver, thanks Antoine.

Changes since v1:
 - fix typos and add a comment, thanks Florian.
 - check for "addr < 0" in phy_package_join()
 - remove multiple blank lines and make "checkpatch.pl --strict" happy

Changes since RFC:
 - check return code of kzalloc()
 - fix local variable ordering (reverse christmas tree)
 - add priv_size argument to phy_package_join()
 - add Tested-by tag, thanks Vladimir.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>