[PATCH] powerpc: Merge ipcbuf.h

This patch merges ppc32 and ppc64 versions of ipcbuf.h.  The merge is
essentially trivial, since the structure defined in each version was
already identical.  Only wrinkle is that the merged version now
includes linux/types.h in order to get the fixed width integer types.
In fact, the old versions probably should have been including that
anyway, since the file uses various __kernel_*_t types.

Built and booted on G5, built for 32-bit pmac, but not booted, since
the merge tree currently doesn't boot there.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>