i2c-intel-mid: support for Moorestown and Medfield platform

(Updated to address Ben's comments. With regard to the message segment
 restriction it's not something we hit on the actual platform so while
 I will investigate that further I don't think its a blocker to submission.
 At worst its a spot over-restrictive)

From: Wen Wang <wen.w.wang@intel.com>

Initial release of the driver. Updated and verified on hardware.

Cleaned up as follows

Alan Cox:
   Squash down the switches into tables, and use the PCI ident field. We
   could perhaps take this further and put the platform and port number into
   this.
   uint32t -> u32
   bracketing of case statements
   spacing and '!' usage
   Check the speed (which is now 0/1/2) is valid and ignore otherwise.
   Fix remaining problems/suggestions from Jean's review
   Fix items from Ben's review

Arjan van de Ven:
   Initial power management hooks

Yong Wang <youg.y.wang@intel.com>:
   Shared IRQ support

Wen Wang <wen.w.wang@intel.com>:
   D3 support
   Fixes for OCT test runs
   Interrupt optimisations

Hong Liu <hong.liu@intel.com>
   The runtime PM code is working on the wrong device (i2c_adapter->dev).
   The correct one should be pci_dev->dev. This breaks attached i2c
   slave devices with runtime PM enabled. Slave device needs to runtime
   resume parent device before runtime resuming itself, but we always get
   error since we don't have pm_runtime callback for i2c_adapter->dev.

Bin Yang <bin.yang@intel.com>:
   Update speed table

Saadi Maalem <saadi.maalem@intel.com>:
   Clear all interrupts in the hardware init

Celine Chotard <celinex.chotard@intel.com>:
   Correct ordering of clear/disable of IRQs

Signed-off-by: Wen Wang <wen.w.wang@intel.com>
Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Signed-off-by: Hong Liu <hong.liu@intel.com>
Signed-off-by: Bin Yang <bin.yang@intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>