Documentation: Use "while" instead of "whilst"

Whilst making an unrelated change to some Documentation, Linus sayeth:

  | Afaik, even in Britain, "whilst" is unusual and considered more
  | formal, and "while" is the common word.
  |
  | [...]
  |
  | Can we just admit that we work with computers, and we don't need to
  | use þe eald Englisc spelling of words that most of the world never
  | uses?

dictionary.com refers to the word as "Chiefly British", which is
probably an undesirable attribute for technical documentation.

Replace all occurrences under Documentation/ with "while".

Cc: David Howells <dhowells@redhat.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michael Halcrow <mhalcrow@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt
index 389fcd4..ce0c1a9 100644
--- a/Documentation/serial/serial-rs485.txt
+++ b/Documentation/serial/serial-rs485.txt
@@ -75,7 +75,7 @@
 	/* Set rts delay after send, if needed: */
 	rs485conf.delay_rts_after_send = ...;
 
-	/* Set this flag if you want to receive data even whilst sending data */
+	/* Set this flag if you want to receive data even while sending data */
 	rs485conf.flags |= SER_RS485_RX_DURING_TX;
 
 	if (ioctl (fd, TIOCSRS485, &rs485conf) < 0) {