Remove readline dependency to fix license conflict issue

Based on the below discussion,
disable ipmi shell to remove the readline dependency.
Since it has license conflict with openssl:
https://lists.ozlabs.org/pipermail/openbmc/2019-November/019678.html

Tested:
Ipmi shell does not work
Ipmitool is not linked to libreadline

Signed-off-by: Yong Li <yong.b.li@linux.intel.com>
Change-Id: I17b3edc59de813effaa83e99c8dfcd5906427c92
diff --git a/recipes-phosphor/ipmi/ipmitool_%.bbappend b/recipes-phosphor/ipmi/ipmitool_%.bbappend
index 5f25f5d..d52f330 100644
--- a/recipes-phosphor/ipmi/ipmitool_%.bbappend
+++ b/recipes-phosphor/ipmi/ipmitool_%.bbappend
@@ -13,6 +13,6 @@
 S = "${WORKDIR}/git"
 LIC_FILES_CHKSUM = "file://${S}/COPYING;md5=9aa91e13d644326bf281924212862184"
 
-EXTRA_OECONF_append = " --enable-intf-dbus DEFAULT_INTF=dbus "
+EXTRA_OECONF_append = " --disable-ipmishell --enable-intf-dbus DEFAULT_INTF=dbus "
 
 PV = "1.8.18+git${SRCPV}"