kbuild: move scripts/basic/docproc.c to scripts/docproc.c

Move docproc from scripts/basic to scripts so it is only built for *doc
targets instead of every time the kernel is built.
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 8436b01..3cebfa0 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -73,7 +73,7 @@
 ###
 #External programs used
 KERNELDOC = $(srctree)/scripts/kernel-doc
-DOCPROC   = $(objtree)/scripts/basic/docproc
+DOCPROC   = $(objtree)/scripts/docproc
 
 XMLTOFLAGS = -m $(srctree)/Documentation/DocBook/stylesheet.xsl
 XMLTOFLAGS += --skip-validation