Add scsi directory

This CL exports bionic/libc/kernel/android/scsi directory
to enable the usage of header files (e.g. sg.h) on that directory.

Test: Build AOSP 1187028
Change-Id: If580fcbc67378fab42d4f14cca1de337b603b673
diff --git a/libc/Android.bp b/libc/Android.bp
index c5ea4c5..d002e50 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -2226,6 +2226,7 @@
     export_preprocessed_headers: ["include"],
     native_bridge_supported: true,
     export_include_dirs: [
+        "kernel/android/scsi",
         "kernel/android/uapi",
         "kernel/uapi",
     ],