remove the raw driver

The raw driver used to provide direct unbuffered access to block devices
before O_DIRECT was invented.  It has been obsolete for more than a
decade.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/lkml/Pine.LNX.4.64.0703180754060.6605@CPE00045a9c397f-CM001225dbafb6/


Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210531072526.97052-1-hch@lst.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>