PEL: Print list of PELs

PelTool commands for printing a list of PELs.

PEL list sample:

{
	"0x50000004": {
		"SRC": "BD8D1001",
		"PLID": "0x50000004",
		"CreatorID": "BMC",
		"Subsystem": "bmc_firmware",
		"Commit Time": "10/24/2019  15:50:08",
		"Sev": "unrecoverable",
 		"CompID": "0x1000"
 	}

}

Change-Id: Ifd864a6561c09de098689195edcf107b3fe550e3
Signed-off-by: Aatir <aatrapps@gmail.com>
diff --git a/extensions/openpower-pels/pel_values.hpp b/extensions/openpower-pels/pel_values.hpp
index 9d49dbe..8d86acf 100644
--- a/extensions/openpower-pels/pel_values.hpp
+++ b/extensions/openpower-pels/pel_values.hpp
@@ -25,6 +25,14 @@
 using PELValues = std::vector<PELFieldValue>;
 
 /**
+ * @brief Helper function to get values from lookup tables.
+ * @return std::string - the value
+ * @param[in] uint8_t - field to get value for
+ * @param[in] PELValues - lookup table
+ */
+std::string getValue(const uint8_t field, const pel_values::PELValues& values);
+
+/**
  * @brief Find the desired entry in a PELValues table based on the
  *        field value.
  *