manibuilder: Move environment overrides into new Makefile.env

Change-Id: I7e1db64ab04c99a472770123865589278778e5f3
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/73775
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/util/manibuilder/Makefile b/util/manibuilder/Makefile
index 5611de8..3ae1e15 100644
--- a/util/manibuilder/Makefile
+++ b/util/manibuilder/Makefile
@@ -16,6 +16,7 @@
 
 ident = $(subst /,_,$(subst :,_,$(subst \:,_,$(1))))
 
+include Makefile.env
 include Makefile.anita
 
 # $(1): mani tag
@@ -45,14 +46,6 @@
 	[ $$(docker image ls -q mani/$*) ] \
 		|| $(MAKE) $*-build $(if $(QUIET_SETUP),>/dev/null 2>/dev/null)
 
-$(ALMALINUX_TAGS) $(filter centos%,$(MULTIARCH_TAGS)): CC=cc
-djgpp\:6.1.0: CC=ccache i586-pc-msdosdjgpp-gcc
-djgpp\:6.1.0: STRIP=i586-pc-msdosdjgpp-strip
-djgpp\:6.1.0: LIBS_BASE=../
-djgpp\:6.1.0: MAKEARGS+=strip CONFIG_JLINK_SPI=no
-$(filter alpine% centos%,$(MULTIARCH_TAGS)): MAKEARGS+=CONFIG_JLINK_SPI=no
-$(filter %-xenial %-stretch,$(MULTIARCH_TAGS)): MAKEARGS+=CONFIG_JLINK_SPI=no
-$(filter centos%,$(MULTIARCH_TAGS)): MAKEARGS+=WARNERROR=no
 $(ALL_TAGS): export QUIET_SETUP=$(QUIET_TEST)
 $(ALL_TAGS): export TEST_REMOTE?=$(if $(TEST_LOCAL),\
 					git://mani-git/flashrom.git,\