doc: convert UIO howto from docbook to sphinx

Converted with tmplcvt. Only some tiny things needed manual fixing.
Signed-off-by: Alexander Dahl <post@lespocky.de>
Cc: Hans-Jürgen Koch <hjk@hansjkoch.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/DocBook/Makefile

@@ -11,7 +11,7 @@ DOCBOOKS := z8530book.xml  \
 	    writing_usb_driver.xml networking.xml \
 	    kernel-api.xml filesystems.xml lsm.xml kgdb.xml \
 	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
-	    genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
+	    genericirq.xml s390-drivers.xml scsi.xml \
 	    sh.xml regulator.xml w1.xml \
 	    writing_musb_glue_layer.xml iio.xml
 

Documentation/driver-api/index.rst

@@ -30,6 +30,7 @@ available subsections can be seen below.
    miscellaneous
    vme
    80211/index
+   uio-howto
 
 .. only::  subproject and html
 

MAINTAINERS

@@ -12966,7 +12966,7 @@ USERSPACE I/O (UIO)
 M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
-F:	Documentation/DocBook/uio-howto.tmpl
+F:	Documentation/driver-api/uio-howto.rst
 F:	drivers/uio/
 F:	include/linux/uio*.h