board/mpl: Remove mpl-specific memory test command

The mpl-specfic memory test is only documented for one board, doesn't
compile cleanly, uses improper coding style, and overlaps functionality
with U-Boot's common 'mtest' command, so lets get rid of it.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
CC: d.peter@mpl.ch
CC: d.mueller@elsoft.ch
CC: wd@denx.de
diff --git a/board/mpl/pip405/Makefile b/board/mpl/pip405/Makefile
index 774b59f..fb39ec3 100644
--- a/board/mpl/pip405/Makefile
+++ b/board/mpl/pip405/Makefile
@@ -32,7 +32,7 @@
 	  ../common/flash.o cmd_pip405.o ../common/pci.o \
 	  ../common/isa.o ../common/kbd.o \
 	  ../common/usb_uhci.o \
-	  ../common/memtst.o ../common/common_util.o
+	  ../common/common_util.o
 
 SOBJS	= init.o