UAPI: Make arch/sh/include/uapi/asm/hw_breakpoint.h non-empty

arch/sh/include/uapi/asm/hw_breakpoint.h was emitted by the UAPI disintegration
script as an empty file because the parent file had no UAPI stuff in it,
despite being marked with "header-y".

Unfortunately, the patch program deletes resultant empty files when applying a
kernel patch.

So just stick a comment in there as a placeholder.

Signed-off-by: David Howells <[e-mail]>
cc: Paul Mundt <[e-mail]>
cc: [e-mail]

arch/sh/include/uapi/asm/hw_breakpoint.h

···
+/*
+ * There isn't anything here anymore, but the file must not be empty or patch
+ * will delete it.
+ */