do not build libinput in PDK

- skia is not available in PDK, and it causes build break.

bug: 9528927
Change-Id: I89663e4a4bd52858506e3b52fbf8ca85d9992363
diff --git a/libs/input/Android.mk b/libs/input/Android.mk
index b3d9e64..2a1e762 100644
--- a/libs/input/Android.mk
+++ b/libs/input/Android.mk
@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+ifneq ($(TARGET_BUILD_PDK),true)
+
 LOCAL_PATH:= $(call my-dir)
 
 # libinput is partially built for the host (used by build time keymap validation tool)
@@ -83,3 +85,5 @@
 ifeq (,$(ONE_SHOT_MAKEFILE))
 include $(call first-makefiles-under,$(LOCAL_PATH))
 endif
+
+endif #!PDK