Makefile: Do not show make debug messages

In commit 27af930, the top Makefile was adjusted to the new
boards.cfg format.

But at the same time, -d option was added.

If you configure and make separately, for example
like follows:

    make omap4_panda_config
    make CROSS_COMPILE=<your_compiler_prefix>

it works fine as it did before.

But if you do them in one time like follows:

    make omap4_panda CROSS_COMPILE=<your_compiler_prefix>

The log is sprinkled with annoying make debug messages.

This commit deletes -d option again.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Nishanth Menon  <nm@ti.com>

Makefile

@@ -838,7 +838,7 @@ unconfig:
 
 sinclude $(obj).boards.depend
 $(obj).boards.depend:	boards.cfg
-	@awk '(NF && $$1 !~ /^#/) { print $$7 ": " $$7 "_config; $$(MAKE) -d" }' $< > $@
+	@awk '(NF && $$1 !~ /^#/) { print $$7 ": " $$7 "_config; $$(MAKE)" }' $< > $@
 
 #
 # Functions to generate common board directory names