make: introduce QQ, use when doing CI build

Makefile.base

@@ -17,10 +17,10 @@ all: $(BINDIR)/$(MODULE).a ..nothing
 clean:: ${DIRS:%=CLEAN--%}
 
 ${DIRS:%=ALL--%}:
-	"$(MAKE)" -C ${@:ALL--%=%}
+	$(QQ)"$(MAKE)" -C ${@:ALL--%=%}
 
 ${DIRS:%=CLEAN--%}:
-	"$(MAKE)" -C ${@:CLEAN--%=%} clean
+	$(QQ)"$(MAKE)" -C ${@:CLEAN--%=%} clean
 
 ifeq ($(strip $(SRC)),)
     SRC := $(filter-out $(SRC_NOLTO), $(wildcard *.c))

Makefile.include

@@ -89,6 +89,8 @@ else
   Q=
 endif
 
+QQ=
+
 # Fail on warnings. Can be overridden by `make WERROR=0`.
 WERROR ?= 1
 export WERROR
@@ -211,6 +213,8 @@ ifeq ($(RIOT_CI_BUILD),1)
         $(info CI-build: skipping link step)
         RIOTNOLINK:=1
     endif
+    # be more quiet when building for CI
+    QQ:=@
 endif
 
 # if you want to publish the board into the sources as an uppercase #define
@@ -315,7 +319,7 @@ INCLUDES += $(USEMODULE_INCLUDES_:%=-I%)
 .PHONY: $(USEPKG:%=${BINDIR}/%.a)
 $(USEPKG:%=${BINDIR}/%.a): $(RIOTBUILD_CONFIG_HEADER_C)
 	@mkdir -p ${BINDIR}
-	"$(MAKE)" -C $(RIOTPKG)/$(patsubst ${BINDIR}/%.a,%,$@)
+	$(QQ)"$(MAKE)" -C $(RIOTPKG)/$(patsubst ${BINDIR}/%.a,%,$@)
 
 clean:
 	-@for i in $(USEPKG) ; do "$(MAKE)" -C $(RIOTPKG)/$$i clean ; done

Makefile.vars

@@ -1,4 +1,5 @@
 export Q                     # Used in front of Makefile lines to suppress the printing of the command if user did not opt-in to see them.
+export QQ                    # as Q, but be more quiet
 export QUIET                 # The parameter to use whether to show verbose makefile commands or not.
 
 export APPLICATION           # The application, set in the Makefile which is run by the user.