build: improve performance by avoiding lazy-eval for make shell calls

Avoids lots of redundant calls to mkhash on things like
package/kernel/linux

Signed-off-by: Felix Fietkau <nbd@nbd.name>

include/host-build.mk

@@ -23,7 +23,7 @@ include $(INCLUDE_DIR)/unpack.mk
 include $(INCLUDE_DIR)/depends.mk
 
 BUILD_TYPES += host
-HOST_STAMP_PREPARED=$(HOST_BUILD_DIR)/.prepared$(if $(HOST_QUILT)$(DUMP),,$(shell $(call find_md5,${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(HOST_PREPARED_DEPENDS)))
+HOST_STAMP_PREPARED:=$(HOST_BUILD_DIR)/.prepared$(if $(HOST_QUILT)$(DUMP),,$(shell $(call find_md5,${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(HOST_PREPARED_DEPENDS)))
 HOST_STAMP_CONFIGURED:=$(HOST_BUILD_DIR)/.configured
 HOST_STAMP_BUILT:=$(HOST_BUILD_DIR)/.built
 HOST_BUILD_PREFIX:=$(if $(IS_PACKAGE_BUILD),$(STAGING_DIR_HOSTPKG),$(STAGING_DIR_HOST))

include/package.mk

@@ -56,9 +56,9 @@ ifneq ($(PREV_STAMP_PREPARED),)
   STAMP_PREPARED:=$(PREV_STAMP_PREPARED)
   CONFIG_AUTOREBUILD:=
 else
-  STAMP_PREPARED=$(PKG_BUILD_DIR)/.prepared$(if $(QUILT)$(DUMP),,_$(shell $(call find_md5,${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(PKG_PREPARED_DEPENDS)))
+  STAMP_PREPARED:=$(PKG_BUILD_DIR)/.prepared$(if $(QUILT)$(DUMP),,_$(shell $(call find_md5,${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(PKG_PREPARED_DEPENDS)))
 endif
-STAMP_CONFIGURED=$(PKG_BUILD_DIR)/.configured$(if $(DUMP),,_$(call confvar,$(PKG_CONFIG_DEPENDS)))
+STAMP_CONFIGURED:=$(PKG_BUILD_DIR)/.configured$(if $(DUMP),,_$(call confvar,$(PKG_CONFIG_DEPENDS)))
 STAMP_CONFIGURED_WILDCARD=$(PKG_BUILD_DIR)/.configured_*
 STAMP_BUILT:=$(PKG_BUILD_DIR)/.built
 STAMP_INSTALLED:=$(STAGING_DIR)/stamp/.$(PKG_DIR_NAME)$(if $(BUILD_VARIANT),.$(BUILD_VARIANT),)_installed