Really unexport asm/page.h

Commit ed7b1889

 removed page.h from
include/asm-generic/Kbuild so that it shouldn't get exported.

However, it was redundantly listed in asm-mn10300/Kbuild and
asm-x86/Kbuild too. Remove those as well, so it really stops being
exported on those architectures. Also remove the redundant listing of
ptrace.h and termios.h from mn10300.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>