[ARM] 5437/1: Add documentation for "nohlt" kernel parameter

As per discussion in:
http://marc.info/?l=linux-arm-kernel&m=123633652517391&w=2

Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Documentation/kernel-parameters.txt

@@ -1513,7 +1513,9 @@ and is between 256 and 4096 characters. It is defined in the file
 
 	noclflush	[BUGS=X86] Don't use the CLFLUSH instruction
 
-	nohlt		[BUGS=ARM,SH]
+	nohlt		[BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
+			wfi(ARM) instruction doesn't work correctly and not to
+			use it. This is also useful when using JTAG debugger.
 
 	no-hlt		[BUGS=X86-32] Tells the kernel that the hlt
 			instruction doesn't work correctly and not to