Enable BMC patching from the /usr/local path

This commit enables patches from the /usr/local path by replacing
absolute paths to /usr/sbin or /usr/bin in every service file with
"/usr/bin/env ". Additionally, SyslogIdentifier is added to each
file to ensure that journal entries are still distinct.

In two cases, service files also had to change due to references
to ${{PATH}}, which doesn't work with /usr/bin/env. These
references - and the corresponding definitions - were changed to
${{DEVPATH}}.

Resolves openbmc/openbmc#2149

Change-Id: I12c5c6e5101eef6820b985a563313836250ff2c7
Signed-off-by: Michael Tritz <mtritz@us.ibm.com>
diff --git a/common/recipes-phosphor/console/obmc-console/obmc-console@.service b/common/recipes-phosphor/console/obmc-console/obmc-console@.service
index e28b069..26e452c 100644
--- a/common/recipes-phosphor/console/obmc-console/obmc-console@.service
+++ b/common/recipes-phosphor/console/obmc-console/obmc-console@.service
@@ -4,7 +4,8 @@
 After=dev-%i.device
 
 [Service]
-ExecStart={sbindir}/obmc-console-server --config {sysconfdir}/obmc-console.conf %i
+ExecStart=/usr/bin/env obmc-console-server --config {sysconfdir}/obmc-console.conf %i
+SyslogIdentifier=obmc-console-server
 Restart=always
 
 [Install]