x86: remove NexGen support

It is claimed that NexGen CPUs were never shipped:

   http://lkml.org/lkml/2008/4/20/179

Also, the kernel support for these chips has been broken for
a long time, the code intended to support NexGen thereby being
essentially dead.

As an outcome of the discussion that can be found using the URL
above, this patch removes the NexGen support altogether.

The changes in this patch survived a defconfig build for i386, a
couple of successful randconfig builds, as well as a runtime test,
which consisted in booting a 32-bit x86 box up to the shell prompt.

Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 57072f2..4da3cdb 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -21,8 +21,8 @@
 
 	  Here are the settings recommended for greatest speed:
 	  - "386" for the AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI
-	  486DLC/DLC2, UMC 486SX-S and NexGen Nx586.  Only "386" kernels
-	  will run on a 386 class machine.
+	  486DLC/DLC2, and UMC 486SX-S.  Only "386" kernels will run on a 386
+	  class machine.
 	  - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or
 	  SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S.
 	  - "586" for generic Pentium CPUs lacking the TSC