intel/common/block/i2c: Add common block for I2C and use the same in SoCs

In the intel/common/block
* Move I2C common code from intel/common to intel/common/block.
* Split the code into common, early init and post mem init stages and put it
  in lpss_i2c.c, i2c_early.c and i2c.c respectively.
* Declare functions for getting platform specific i2c bus config and
  mapping bus to devfn and vice versa, that have to be implemented by SoC.

In skylake/apollolake
* Stop using code from soc/intel/common/lpss_i2c.c.
* Remove early i2c initialization code from bootblock.
* Refactor i2c.c file to implement SoC specific methods
  required by the I2C IP block.

Change-Id: I4d91a04c22e181e3a995112cce6d5f0324130b81
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/19468
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/skylake/chip.h

@@ -22,11 +22,11 @@
 #include <arch/acpi_device.h>
 #include <device/i2c.h>
 #include <intelblocks/gspi.h>
+#include <intelblocks/lpss_i2c.h>
 #include <stdint.h>
 #include <soc/gpio_defs.h>
 #include <soc/gpe.h>
 #include <soc/irq.h>
-#include <soc/intel/common/lpss_i2c.h>
 #include <soc/pci_devs.h>
 #include <soc/pmc.h>
 #include <soc/serialio.h>