sound/core/pcm_native.c was assuming that all architectures implement
io_remap_page_range() in the same way.  They don't, so the sparc64 build
broke.

mmap callback is added to PCM ops.  The driver can implement its own mmap
method.

Also, mmapping of the status and control records is available only on known
coherent architectures now.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>