package/htpdate: fix static openssl build

Fix the following static build failure with openssl raised since bump to
version 1.3.3 in commit 163509a8e0d558e6339c5489f072dfe805e0cc34:

/home/buildroot/autobuild/instance-3/output-1/host/opt/ext-toolchain/bin/../lib/gcc/sh4-buildroot-linux-uclibc/10.3.0/../../../../sh4-buildroot-linux-uclibc/bin/ld: /home/buildroot/autobuild/instance-3/output-1/host/sh4-buildroot-linux-uclibc/sysroot/usr/lib/libssl.a(rec_layer_d1.o): in function `DTLS_RECORD_LAYER_new':
rec_layer_d1.c:(.text+0x124): undefined reference to `CRYPTO_malloc'

Fixes:
 - http://autobuild.buildroot.org/results/75ad8515916dfa056b17c97fdd95c7eb4d83a304

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/htpdate/0001-Allow-SSL_LIBS-to-be-configured-from-environment.patch

@@ -0,0 +1,37 @@
+From 4ba90fedd553c3b06c925fb6ff5245a5dcabace9 Mon Sep 17 00:00:00 2001
+From: Eddy Vervest <eddy@vervest.org>
+Date: Sat, 29 Jan 2022 10:58:13 +0100
+Subject: [PATCH] Allow SSL_LIBS to be configured from environment
+
+[Retrieved from:
+https://github.com/twekkel/htpdate/commit/4ba90fedd553c3b06c925fb6ff5245a5dcabace9]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ Makefile | 7 ++++---
+ 1 file changed, 4 insertions(+), 3 deletions(-)
+
+diff --git a/Makefile b/Makefile
+index 4796efa..cf077e6 100644
+--- a/Makefile
++++ b/Makefile
+@@ -2,8 +2,9 @@ prefix = $(DESTDIR)/usr
+ bindir = ${prefix}/sbin
+ mandir = ${prefix}/share/man
+ 
+-CC     ?= gcc
+-CFLAGS += -Wall -std=c11 -pedantic -O2
++CC       ?= gcc
++CFLAGS   += -Wall -std=c11 -pedantic -O2
++SSL_LIBS ?= -lssl
+ 
+ INSTALL ?= install -c
+ STRIP   ?= strip -s
+@@ -14,7 +15,7 @@ htpdate: htpdate.c
+ 	$(CC) $(CFLAGS) -o htpdate htpdate.c
+ 
+ https: htpdate.c
+-	$(CC) $(CFLAGS) -DENABLE_HTTPS -o htpdate htpdate.c -lssl
++	$(CC) $(CFLAGS) -DENABLE_HTTPS -o htpdate htpdate.c $(SSL_LIBS)
+ 
+ install: all
+ 	$(STRIP) htpdate

package/htpdate/htpdate.mk

@@ -10,7 +10,9 @@ HTPDATE_LICENSE = GPL-2.0+
 HTPDATE_LICENSE_FILES = LICENSE
 
 ifeq ($(BR2_PACKAGE_OPENSSL),y)
-HTPDATE_BUILD_OPTS = https
+HTPDATE_BUILD_OPTS = \
+	https \
+	SSL_LIBS="`$(PKG_CONFIG_HOST_BINARY) --libs openssl`"
 HTPDATE_DEPENDENCIES += openssl host-pkgconf
 endif