Add an option to exclude libuserlayer from host-ipmid

Change-Id: I8e14cfd3719c7fbef739f2aa01771bc4321ce290
Signed-off-by: Ofer Yehielli <ofery@google.com>
Tested: Enabled the exclude libuserlayer flag in
recipes-phosphor/ipmi/phosphor-ipmi-host_%.bbappend
+EXTRA_OECONF_append_xxx = " --disable-libuserlayer"
+HOSTIPMI_PROVIDER_LIBRARY_remove_xxx = "libusercmds.so"
+NETIPMI_PROVIDER_LIBRARY_remove_xxx = "libusercmds.so"
Clean build and test that userlayer.so doesn't get included in the build
diff --git a/user_channel/Makefile.am b/user_channel/Makefile.am
index 3860a39..747c4c8 100644
--- a/user_channel/Makefile.am
+++ b/user_channel/Makefile.am
@@ -12,7 +12,12 @@
 	-DBOOST_ASIO_DISABLE_THREADS \
 	-DBOOST_ALL_NO_LIB
 
-lib_LTLIBRARIES = libuserlayer.la libchannellayer.la
+
+lib_LTLIBRARIES =
+
+if FEATURE_LIBUSERLAYER
+
+lib_LTLIBRARIES += libuserlayer.la
 libuserlayer_la_SOURCES = \
 	user_layer.cpp \
 	user_mgmt.cpp \
@@ -29,7 +34,9 @@
 libuserlayer_la_CXXFLAGS = \
 	-I$(top_srcdir) \
 	$(COMMON_CXX)
+endif
 
+lib_LTLIBRARIES += libchannellayer.la
 libchannellayer_la_SOURCES = \
 	channel_mgmt.cpp \
 	channel_layer.cpp