[patch] Add Mac OS X building directions to readme file

[Programmingkid]

This patch gives the user a link in the README file, to directions on how to build on Mac OS X. The current directions in the README file are not enough.

signed-off-by: John Arbuckle

Index: README
===================================================================
--- README	(revision 1102)
+++ README	(working copy)
@@ -35,6 +35,10 @@

make run        - run unix example.

+
+*Please refer to these directions when building on Mac OS X:
+http://www.openfirmware.info/How_to_build_OpenBIOS_on_Mac_OS_X
+

How OpenBIOS works
 ------------------