partition: set fbe.data.wrappedkey automatically via flag

In change I79c2855d577156670b45c10c7c7b1fcd9fece8d9 we introduced a
property to enable wrappedkey mode. This change supports an extra
`wrappedkey` flag in fstab to automatically set the property to true.

Change-Id: I4f060d4ed6b2a5680649b8746dfa7fd903fe2d35
(cherry picked from commit 40ed06e850de2dc7cc06c2e647688212563f1ec2)

partition.cpp

@@ -158,6 +158,7 @@ enum TW_FSTAB_FLAGS {
 	TWFLAG_FORMATTABLE,
 	TWFLAG_RESIZE,
 	TWFLAG_KEYDIRECTORY,
+	TWFLAG_WRAPPEDKEY,
 };
 
 /* Flags without a trailing '=' are considered dual format flags and can be
@@ -202,6 +203,7 @@ const struct flag_list tw_flags[] = {
 	{ "formattable",            TWFLAG_FORMATTABLE },
 	{ "resize",                 TWFLAG_RESIZE },
 	{ "keydirectory=",          TWFLAG_KEYDIRECTORY },
+	{ "wrappedkey",             TWFLAG_WRAPPEDKEY },
 	{ 0,                        0 },
 };
 
@@ -883,6 +885,13 @@ void TWPartition::Apply_TW_Flag(const unsigned flag, const char* str, const bool
 				LOGINFO("FBE contents '%s', filenames '%s'\n", FBE_contents.c_str(), FBE_filenames.c_str());
 			}
 			break;
+		case TWFLAG_WRAPPEDKEY:
+			// Set fbe.data.wrappedkey to true
+			{
+				property_set("fbe.data.wrappedkey", "true");
+				LOGINFO("FBE wrapped key enabled\n");
+			}
+			break;
 		case TWFLAG_FLASHIMG:
 			Can_Flash_Img = val;
 			break;