Drop kernel configs p-4.4.

4.4 has reached EOL.

Devices running 4.4 kernel will no longer be able to update
to the latest Android version.

Test: TH
Change-Id: I5b9d0bc6c0cf422cb53193fee4e118ea1bfe2b70
diff --git a/compatibility_matrices/Android.bp b/compatibility_matrices/Android.bp
index 524242f..4dc3f6c 100644
--- a/compatibility_matrices/Android.bp
+++ b/compatibility_matrices/Android.bp
@@ -28,7 +28,6 @@
         "compatibility_matrix.3.xml",
     ],
     kernel_configs: [
-        "kernel_config_p_4.4",
         "kernel_config_p_4.9",
         "kernel_config_p_4.14",
     ],