Don't build x86-only code on arm/riscv.

The upstream makefiles include this for x86 and x86-64, so I've done the same.

Bug: http://b/351833436
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:9848999cd77cfd69b5a355c6e237b3596ffa0459)
Merged-In: I5dfbd3a505ad7a656eeb677c68d3782572759e91
Change-Id: I5dfbd3a505ad7a656eeb677c68d3782572759e91
diff --git a/Android.bp b/Android.bp
index 8d22c88..1153443 100644
--- a/Android.bp
+++ b/Android.bp
@@ -90,12 +90,20 @@
         "lib/caps.c",
         "lib/sysfs.c",
         "lib/proc.c",
-        "lib/i386-ports.c",
         "lib/mmio-ports.c",
         "lib/ecam.c",
         "lib/physmem-posix.c",
     ],
 
+    arch: {
+        x86: {
+            srcs: ["lib/i386-ports.c"],
+        },
+        x86_64: {
+            srcs: ["lib/i386-ports.c"],
+        },
+    },
+
     generated_headers: [
         "libpci_config",
         "libpci_includes",