remove Documentation/smp.txt

After seeing the filename I'd have expected something about the
implementation of SMP in the Linux kernel - not some notes on kernel
configuration and building trivialities noone would search at this
place.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Alan Cox <alan@redhat.com>
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index c613d5f..1a99bdd 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -531,8 +531,8 @@
 	  singleprocessor machines. On a singleprocessor machine, the kernel
 	  will run faster if you say N here.
 
-	  See also the <file:Documentation/smp.txt>, and the SMP-HOWTO
-	  available at <http://www.tldp.org/docs.html#howto>.
+	  See also the SMP-HOWTO available at
+	  <http://www.tldp.org/docs.html#howto>.
 
 	  If you don't know what to do here, say N.