Documentation: add pointer to name_to_dev_t for root= values

Update kernel-parameters.txt to point users to the authoritative comment
for name_to_dev_t.  In addition, updates other places where some
name_to_dev_t behavior was discussed.  All other references to root=
appear to be for explicit sample usage or just side comments when
discussing other kernel parameters.

Signed-off-by: Will Drewry <wad@chromium.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/frv/booting.txt b/Documentation/frv/booting.txt
index ace200b..37c4d84 100644
--- a/Documentation/frv/booting.txt
+++ b/Documentation/frv/booting.txt
@@ -106,13 +106,20 @@
       To use the first on-chip serial port at baud rate 115200, no parity, 8
       bits, and no flow control.
 
-  (*) root=/dev/<xxxx>
+  (*) root=<xxxx>
 
-      This specifies the device upon which the root filesystem resides. For
-      example:
+      This specifies the device upon which the root filesystem resides. It
+      may be specified by major and minor number, device path, or even
+      partition uuid, if supported.  For example:
 
 	/dev/nfs	NFS root filesystem
 	/dev/mtdblock3	Fourth RedBoot partition on the System Flash
+	PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF/PARTNROFF=1
+		first partition after the partition with the given UUID
+	253:0		Device with major 253 and minor 0
+
+      Authoritative information can be found in
+      "Documentation/kernel-parameters.txt".
 
   (*) rw