IB/ipath: kbuild infrastructure

Integrate the ipath core and OpenIB drivers into the kernel build
infrastructure.  Add entry to MAINTAINERS.

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/Makefile b/drivers/Makefile
index 4249552..2449ec5 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -70,6 +70,7 @@
 obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_MMC)		+= mmc/
 obj-$(CONFIG_INFINIBAND)	+= infiniband/
+obj-$(CONFIG_IPATH_CORE)	+= infiniband/
 obj-$(CONFIG_SGI_SN)		+= sn/
 obj-y				+= firmware/
 obj-$(CONFIG_CRYPTO)		+= crypto/