Manually update makefile for vndk-sp hidl libs.

vndk-sp is not automatically tagged by hidl-gen.
For vndk-sp libs, "support_system_process: true" is manually added
in "vndk" property.

Bug: 63866913
Test: build and boot with BOARD_VNDK_VERSION=current
Change-Id: I2b18d691411e58dc55bcdfa39ecb3659242c8437
diff --git a/graphics/common/1.0/Android.bp b/graphics/common/1.0/Android.bp
index 8450231..86438c1 100644
--- a/graphics/common/1.0/Android.bp
+++ b/graphics/common/1.0/Android.bp
@@ -41,6 +41,7 @@
     vendor_available: true,
     vndk: {
         enabled: true,
+        support_system_process: true,
     },
     shared_libs: [
         "libhidlbase",