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
3 files changed