MRW: If bus object doesn't have I2C_ADDRESS property, get it from I2C slave
MRW: If bus object doesn't have I2C_ADDRESS property, get it from I2C slave

This change amends the processMrw.pl script to get the I2C_ADDRESS property
from the I2C slave if it is not available from the I2C bus object.  Without
this change, the OpenPOWER MRWs populate invalid I2C addresses in the
HDAT I2C attributes, which Hostboot then ignores, resulting in OS not seeing
all the I2C devices

Change-Id: I6a5f1193f31b124193641174229b5f9433b41d4c
CQ: SW438846
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/62968
Tested-by: Jenkins Server <8e3f934e4c44875bc48d33da3ea13d93ba9a233f@us.ibm.com>
Tested-by: Jenkins OP Build CI <e610bd72261d3c0a48f1e8ae36832ab00774d426@us.ibm.com>
Tested-by: FSP CI Jenkins <aa9e4d9ac7cd25905e9c0dd36d4150516e73dd86@us.ibm.com>
Tested-by: Jenkins OP HW <0eb0fff262f74a65a832afbcc7b153e391c9a3fd@us.ibm.com>
Reviewed-by: Daniel M. Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>

open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot