Remove non-UAPI Kbuild files that have become empty as a result of UAPI
disintegration.  They used to have only header-y lines in them and those have
now moved to the Kbuild files in the corresponding uapi/ directories.

Possibly these should not be removed but rather have a comment inserted to say
they are intentionally left blank.  This would make it easier to add generated
header lines in future without having to restore the infrastructure.

Note that at this point not all the UAPI disintegration parts have been merged,
so it is likely that more empty Kbuild files will turn up.

It is probably necessary to make the files non-empty to prevent the patch
program from automatically deleting them when it reduces them to nothing.

Signed-off-by: David Howells <dhowells@redhat.com>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>

Add a filesystem API for <linux/spi/spi.h> stack.  The initial version of
this interface is purely synchronous.

dbrownell@users.sourceforge.net:

 Cleaned up, bugfixed; much simplified; added preliminary documentation.

 Works with mdev given CONFIG_SYSFS_DEPRECATED; and presumably udev.

 Updated SPI_IOC_MESSAGE ioctl to full spi_message semantics, supporting
 groups of one or more transfers (each of which may be full duplex if
 desired).

 This is marked as EXPERIMENTAL with an explicit disclaimer that the API
 (notably the ioctls) is subject to change.

Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>