initrdscripts: add /etc/ipmi_pass to update preservation list

Previously a firmware update via a *.static.mtd.all.tar file would
preserve /etc/shadow, but not /etc/ipmi_pass.  A non-default password
would thus continue to work for HTTP and SSH authentication, but IPMI
authentication would be broken.  With /etc/ipmi_pass preserved across
such an update, IPMI continues to work as it should.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Change-Id: Iba378a20fe90c9bbe8a2a23dde851965ceda17f5
diff --git a/meta-phosphor/recipes-phosphor/initrdscripts/files/whitelist b/meta-phosphor/recipes-phosphor/initrdscripts/files/whitelist
index 20f1ec2..cfe4280 100644
--- a/meta-phosphor/recipes-phosphor/initrdscripts/files/whitelist
+++ b/meta-phosphor/recipes-phosphor/initrdscripts/files/whitelist
@@ -1,6 +1,7 @@
 /etc/dropbear/dropbear_rsa_host_key
 /etc/group
 /etc/gshadow
+/etc/ipmi_pass
 /etc/machine-id
 /etc/passwd
 /etc/resolv.conf