libtommath: use $(TARGET_MAKE_ENV) when calling $(MAKE)

Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libtommath/libtommath.mk

@@ -13,11 +13,11 @@ LIBTOMMATH_INSTALL_STAGING = YES
 LIBTOMMATH_INSTALL_TARGET = NO  # only static library
 
 define LIBTOMMATH_BUILD_CMDS
-	$(MAKE) -C $(@D) $(TARGET_CONFIGURE_OPTS) CFLAGS="-I./ -fPIC $(TARGET_CFLAGS)"
+	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D) $(TARGET_CONFIGURE_OPTS) CFLAGS="-I./ -fPIC $(TARGET_CFLAGS)"
 endef
 
 define LIBTOMMATH_INSTALL_STAGING_CMDS
-	$(MAKE) -C $(@D) DESTDIR="$(STAGING_DIR)" install
+	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D) DESTDIR="$(STAGING_DIR)" install
 endef
 
 $(eval $(generic-package))