allow using programs over than wget to download sources

based on patch by Michael Forney, but using a plain variable without
without the need for $(call ...). I used a different name for the
variable so that it won't break if anyone has an HTTP_GET variable for
use with the original patch in their config.mak.

Makefile

@@ -24,6 +24,8 @@ MUSL_REPO = git://git.musl-libc.org/musl
 
 LINUX_SITE = https://cdn.kernel.org/pub/linux/kernel
 
+DL_CMD = wget -c -O
+
 BUILD_DIR = build-$(TARGET)
 
 -include config.mak
@@ -65,7 +67,7 @@ $(SOURCES):
 
 $(SOURCES)/config.sub: | $(SOURCES)
 	mkdir -p $@.tmp
-	cd $@.tmp && wget -c -O $(notdir $@) "http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=$(CONFIG_SUB_REV)"
+	cd $@.tmp && $(DL_CMD) $(notdir $@) "http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=$(CONFIG_SUB_REV)"
 	cd $@.tmp && touch $(notdir $@)
 	cd $@.tmp && sha1sum -c $(CURDIR)/hashes/$(notdir $@).$(CONFIG_SUB_REV).sha1
 	mv $@.tmp/$(notdir $@) $@
@@ -73,7 +75,7 @@ $(SOURCES)/config.sub: | $(SOURCES)
 
 $(SOURCES)/%: hashes/%.sha1 | $(SOURCES)
 	mkdir -p $@.tmp
-	cd $@.tmp && wget -c -O $(notdir $@) $(SITE)/$(notdir $@)
+	cd $@.tmp && $(DL_CMD) $(notdir $@) $(SITE)/$(notdir $@)
 	cd $@.tmp && touch $(notdir $@)
 	cd $@.tmp && sha1sum -c $(CURDIR)/hashes/$(notdir $@).sha1
 	mv $@.tmp/$(notdir $@) $@

config.mak.dist

@@ -41,6 +41,11 @@
 # ISL_VER =
 # LINUX_VER =
 
+# By default source archives are downloaded with wget. curl is also an option.
+
+# DL_CMD = wget -c -O
+# DL_CMD = curl -C - -L -o
+
 # Something like the following can be used to produce a static-linked
 # toolchain that's deployable to any system with matching arch, using
 # an existing musl-targeted cross compiler. This only # works if the