Add -mcpu=generic to arm32 build target

Bug: 159925616
Test: lunch walleye-userdebug && mm
Change-Id: I07888f62185b15b693f0082566abe807755c47eb
diff --git a/Android.bp b/Android.bp
index 0503e9c..7b4b22e 100644
--- a/Android.bp
+++ b/Android.bp
@@ -63,6 +63,7 @@
                 "src/arm/linux/aarch32-isa.c",
             ],
             cflags: [
+                "-mcpu=generic",
                 "-march=armv7-a",
             ],
        },