unexport asm/shmparam.h

SHMLBA cant possible be used in userspace, see sparc versions of that header.

Do not export asm/shmparam.h during make headers_install_all
This removes another uservisible place of PAGE_SIZE

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>