Populate Protocol property in Item.Drive interface

By populating this property, bmcweb can populate the "Protocol"
property in the Drive schema.

Tested:
$ busctl get-property xyz.openbmc_project.eStoraged \
  /xyz/openbmc_project/inventory/storage/mmcblk0 \
  xyz.openbmc_project.Inventory.Item.Drive Protocol
s "xyz.openbmc_project.Inventory.Item.Drive.DriveProtocol.eMMC"

Signed-off-by: John Wedig <johnwedig@google.com>
Change-Id: I2bd19190c445ce57f3d867ffbb437c1a4a370b51
diff --git a/src/test/estoraged_test.cpp b/src/test/estoraged_test.cpp
index 3d31112..5ad8f00 100644
--- a/src/test/estoraged_test.cpp
+++ b/src/test/estoraged_test.cpp
@@ -47,6 +47,7 @@
     const std::string testSerialNumber = "ABCDEF1234";
     const std::string testLocationCode = "U102020";
     const std::string testDriveType = "SSD";
+    const std::string testDriveProtocol = "eMMC";
     std::ofstream testFile;
     std::string passwordString;
     std::vector<uint8_t> password;
@@ -92,7 +93,8 @@
             *objectServer, testConfigPath, testFileName, testLuksDevName,
             testSize, testLifeTime, testPartNumber, testSerialNumber,
             testLocationCode, ERASE_MAX_GEOMETRY, ERASE_MIN_GEOMETRY,
-            testDriveType, std::move(cryptIface), std::move(fsIface));
+            testDriveType, testDriveProtocol, std::move(cryptIface),
+            std::move(fsIface));
     }
 
     void TearDown() override
diff --git a/src/test/util_test.cpp b/src/test/util_test.cpp
index 86e86e9..e2fdcc3 100644
--- a/src/test/util_test.cpp
+++ b/src/test/util_test.cpp
@@ -144,6 +144,7 @@
     EXPECT_EQ(ERASE_MAX_GEOMETRY, result->eraseMaxGeometry);
     EXPECT_EQ(ERASE_MIN_GEOMETRY, result->eraseMinGeometry);
     EXPECT_EQ("SSD", result->driveType);
+    EXPECT_EQ("eMMC", result->driveProtocol);
 
     /* Delete the dummy files. */
     EXPECT_EQ(3U, std::filesystem::remove_all("mmcblk0"));
@@ -201,6 +202,7 @@
     EXPECT_EQ(5566, result->eraseMaxGeometry);
     EXPECT_EQ(1234, result->eraseMinGeometry);
     EXPECT_EQ("SSD", result->driveType);
+    EXPECT_EQ("eMMC", result->driveProtocol);
 
     /* Delete the dummy files. */
     EXPECT_EQ(3U, std::filesystem::remove_all("mmcblk0"));