classes: Add Android sparse image class

Adds a class to create sparse image files using the Android tools

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/classes/image_types_sparse.bbclass

@@ -0,0 +1,16 @@
+inherit image_types
+
+CONVERSIONTYPES += "sparse"
+CONVERSION_CMD_sparse() {
+    in="${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.${type}"
+    out="${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.${type}.sparse"
+    case "${type}" in
+        ext*)
+            ext2simg "$in" "$out"
+            ;;
+        *)
+            img2simg "$in" "$out"
+            ;;
+    esac
+}
+CONVERSION_DEPENDS_sparse = "android-tools-native"