openssl: tell the build system that we are doing CROSS_COMPILE

So that it will not try to run c_rehash with the just built binaries on
certs/demo.

Fixes openwrt/packages#5432

Reported-by: Val Kulkov <val.kulkov@gmail.com>
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

package/libs/openssl/Makefile

@@ -198,6 +198,7 @@ define Build/Configure
 	# so remove installed stuff first
 	-$(SUBMAKE) -j1 clean-staging
 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
+		CROSS_COMPILE="$(TARGET_CROSS)" \
 		MAKEDEPPROG="$(TARGET_CROSS)gcc" \
 		OPENWRT_OPTIMIZATION_FLAGS="$(TARGET_CFLAGS)" \
 		$(OPENSSL_MAKEFLAGS) \
@@ -209,6 +210,7 @@ TARGET_LDFLAGS += -Wl,--gc-sections
 
 define Build/Compile
 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
+		CROSS_COMPILE="$(TARGET_CROSS)" \
 		CC="$(TARGET_CC)" \
 		ASFLAGS="$(TARGET_ASFLAGS) -I$(PKG_BUILD_DIR)/crypto -c" \
 		AR="$(TARGET_CROSS)ar r" \
@@ -217,6 +219,7 @@ define Build/Compile
 		$(OPENSSL_MAKEFLAGS) \
 		all
 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
+		CROSS_COMPILE="$(TARGET_CROSS)" \
 		CC="$(TARGET_CC)" \
 		ASFLAGS="$(TARGET_ASFLAGS) -I$(PKG_BUILD_DIR)/crypto -c" \
 		AR="$(TARGET_CROSS)ar r" \
@@ -227,11 +230,13 @@ define Build/Compile
 	# Work around openssl build bug to link libssl.so with libcrypto.so.
 	-rm $(PKG_BUILD_DIR)/libssl.so.*.*.*
 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
+		CROSS_COMPILE="$(TARGET_CROSS)" \
 		CC="$(TARGET_CC)" \
 		OPENWRT_OPTIMIZATION_FLAGS="$(TARGET_CFLAGS)" \
 		$(OPENSSL_MAKEFLAGS) \
 		do_linux-shared
 	$(MAKE) -C $(PKG_BUILD_DIR) \
+		CROSS_COMPILE="$(TARGET_CROSS)" \
 		CC="$(TARGET_CC)" \
 		INSTALL_PREFIX="$(PKG_INSTALL_DIR)" \
 		$(OPENSSL_MAKEFLAGS) \