ia32-base.inc: new include file

ia32-base.inc: new include file

This is the ia32-base.inc moved over from meta-intel.  See meta-intel
for the complete history of contributions to this file.

Here's the initial commit text that explains the purpose of this file:

  The meta-intel BSPs currently have a number of machine settings common
  to all - factor these out into a common include file.

  Also add several new intel-specific XSERVER variables for building
  XSERVER variables in BSPs.

Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>