package/git: use pkg-config to get ssl dependencies

On some architectures, atomic binutils are provided by the libatomic
library from gcc. Linking with libatomic is therefore necessary,
otherwise the build fails with:

/home/test/autobuild/run/instance-2/output/host/sparc-buildroot-linux-uclibc/sysroot/usr/lib/libssl.a(ssl_cert.o): In function `CRYPTO_DOWN_REF':
/home/test/autobuild/run/instance-2/output/build/libopenssl-1.1.1a/include/internal/refcount.h:50: undefined reference to `__atomic_fetch_sub_4'

This is often for example the case on sparcv8 32 bit.

To fix this issue, use pkg-config to retrieve openssl dependencies
including atomic library, these dependencies must be passed to
LIB_4_CRYPTO IN GIT_MAKE_OPTS

Fixes:
 - http://autobuild.buildroot.org/results/3093897d14a854a7252b25b2fa1f8fdcbb26c9b7

Signed-off-by: Fabrice Fontaine <[email protected]>
Signed-off-by: Thomas Petazzoni <[email protected]>
(cherry picked from commit 1ae9640)
Signed-off-by: Peter Korsgaard <[email protected]>

package/git/git.mk

@@ -12,9 +12,9 @@ GIT_LICENSE_FILES = COPYING LGPL-2.1
 GIT_DEPENDENCIES = zlib $(TARGET_NLS_DEPENDENCIES)
 
 ifeq ($(BR2_PACKAGE_OPENSSL),y)
-GIT_DEPENDENCIES += openssl
+GIT_DEPENDENCIES += host-pkgconf openssl
 GIT_CONF_OPTS += --with-openssl
-GIT_CONF_ENV_LIBS += $(if $(BR2_STATIC_LIBS),-lz)
+GIT_MAKE_OPTS += LIB_4_CRYPTO="`$(PKG_CONFIG_HOST_BINARY) --libs libssl libcrypto`"
 else
 GIT_CONF_OPTS += --without-openssl
 endif