PEL: Support resolution property

Support resolution property to add callouts

Tested: Created new PEL using busctl and checked for the property to
see if the value is updated. The error log daemon was restarted and the
property is checked again to make sure the value is restored.

Verified serialization of new error log by recreating it on a old code
version to make sure logs are created w/o the new property and the
daemon did not crash.

Result:
root@rainier:~# busctl get-property xyz.openbmc_project.Logging \
 /xyz/openbmc_project/logging/entry/1 xyz.openbmc_project.Logging.\
 Entry Resolution
s "1. Priority: High, Procedure: BMCSP02\n2. Priority: Medium, PN: \
SVCDOCS\n"

Test with location Code:
root@p10bmc:~# busctl get-property xyz.openbmc_project.Logging \
/xyz/openbmc_project/logging/entry/3 xyz.openbmc_project.Logging.Entry \
Resolution
s "1. Location Code: U78DA.ND0.1234567-P0, Priority: Medium, PN: SVCDOCS\n2. \
Priority: Low, Procedure: BMCSP02\n"

Signed-off-by: Vijay Lobo <vijaylobo@gmail.com>
Change-Id: I44eebbf794efeb8e752fff98de7c638c927982cd
diff --git a/extensions/openpower-pels/pel_values.hpp b/extensions/openpower-pels/pel_values.hpp
index 5f8b852..d737267 100644
--- a/extensions/openpower-pels/pel_values.hpp
+++ b/extensions/openpower-pels/pel_values.hpp
@@ -35,8 +35,10 @@
  * @return std::string - the value
  * @param[in] uint8_t - field to get value for
  * @param[in] PELValues - lookup table
+ * @param[in] uint8_t - position in the pel_values table to read
  */
-std::string getValue(const uint8_t field, const pel_values::PELValues& values);
+std::string getValue(const uint8_t field, const pel_values::PELValues& values,
+                     const uint8_t position = pel_values::descriptionPos);
 
 /**
  * @brief Helper function to get value vector from lookup tables.