move HOST_IPMI_LIB_PATH to configure.ac

Per TODO in Makefile.am, move the definition of HOST_IPMI_LIB_PATH from
the Makefile to the configure script.

Change-Id: If39bf1193f4502c239a78e21487566b234b746f8
Signed-off-by: Patrick Venture <venture@google.com>
3 files changed