kconfig: add BOARD Kconfig variable for defining boards

This variable (CONFIG_BOARD) will store the textual form of the
platform name and will be used for locating files related to the
board in the source tree.

Change-Id: I3c8a05ed428451a6785799a5492f0dd14682f208
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2 files changed