sound: Remove OSSlib stuff from linux/soundcard.h

Removed OSSlib stuff from linux/soundcard.h to fix the warnings for
'make headers_check'.

This patch breaks building against OSSlib with the kernel headers
instead of its own headers. It should still work with any
version of the library from the 2003 onwards which provide
their own headers for the latest interface.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>