drm_hwcomposer: Remove hwc2 build targets

All devices in aosp have been migrated to hwc3. Remove the hwc2 build
targets as a first step towards removing hwc2 from this project.

Change-Id: I116e4d13342368e9375b4d96d9598ba058f936a0
Signed-off-by: Drew Davenport <ddavenport@google.com>

Android.bp

diff --git a/Android.bp b/Android.bp
index d6994ac..e7a77bd 100644
--- a/Android.bp
+++ b/Android.bp
@@ -137,32 +137,6 @@
     ],
 }
 
-// Kept only for compatibility with older Android version. Please do not use!
-cc_library_static {
-    name: "drm_hwcomposer",
-    defaults: ["hwcomposer.drm_defaults"],
-    srcs: [":drm_hwcomposer_common"],
-}
-
-cc_library_shared {
-    name: "hwcomposer.drm",
-    defaults: ["hwcomposer.drm_defaults"],
-    srcs: [
-        ":drm_hwcomposer_common",
-        "bufferinfo/legacy/BufferInfoLibdrm.cpp",
-    ],
-    cflags: ["-DUSE_IMAPPER4_METADATA_API"],
-}
-
-cc_library_shared {
-    name: "hwcomposer.drm_minigbm",
-    defaults: ["hwcomposer.drm_defaults"],
-    srcs: [
-        ":drm_hwcomposer_common",
-        "bufferinfo/legacy/BufferInfoMinigbm.cpp",
-    ],
-}
-
 cc_defaults {
     name: "android.hardware.composer.hwc3-service.drm.defaults",