gas/doc/arc: Add nps400 references into the documentation

Add nps400 to the list of acceptable values for the -mcpu command line
switch, and to the .cpu directive.

I've added an extra cross reference from -mcpu to .cpu to improve
navigation of the documentation.

gas/ChangeLog:

	* doc/c-arc.texi (ARC Options): Add nps400 to list of valus for
	-mcpu.  Add cross reference to .cpu directive from -mcpu option.
	(ARC Directives): Add NPS400 to .cpu directive list.

1 files changed, 8 insertions, 2 deletions

diff --git a/gas/doc/c-arc.texi b/gas/doc/c-arc.texi
index a3e18cf..36d3ec0 100644
--- a/gas/doc/c-arc.texi
+++ b/gas/doc/c-arc.texi
@@ -56,6 +56,9 @@ Assemble for ARC 601.  Alias: @code{-mARC601}.
 @cindex @code{mARC700} command line option, ARC
 Assemble for ARC 700.  Aliases: @code{-mA7}, @code{-mARC700}.
 
+@item nps400
+Assemble for NPS400.
+
 @item arcem
 @cindex @code{mEM} command line option, ARC
 Assemble for ARC EM.  Aliases: @code{-mEM}
@@ -66,8 +69,8 @@ Assemble for ARC HS.  Aliases: @code{-mHS}, @code{-mav2hs}.
 
 @end table
 
-Note: the @code{.cpu} directive can to be used to select a core
-variant from within assembly code.
+Note: the @code{.cpu} directive (@pxref{ARC Directives}) can
+to be used to select a core variant from within assembly code.
 
 @cindex @code{-EB} command line option, ARC
 @item -EB
@@ -350,6 +353,9 @@ Assemble for the ARC600 instruction set.
 @item ARC700
 Assemble for the ARC700 instruction set.
 
+@item NPS400
+Assemble for the NPS400 instruction set.
+
 @item EM
 Assemble for the ARC EM instruction set.