gst1-plugins-bad: fix broken dependency for the hls plugin

HLS plugin can be built with nettle or libgcrypt or openssl
cryptographic backend. But current dependency on gnutls is incorrect.
It has been working so far because gnutls depends on nettle.

gst-plugins-bad's build system for HLS allows user to choose which
cryptographic backend to use. If that is not specified, it internally
checks for nettle or libgcrypt or openssl in order. If none of the
cryptographic backend is available, HLS plugin gets disabled internally.

Select cryptographic backend according to which cryptographic packages
are available. If both libgcrypt or openssl are not available, choose
nettle by default.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Signed-off-by: Rahul Bedarkar <rahul.bedarkar@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gstreamer1/gst1-plugins-bad/Config.in

@@ -530,7 +530,7 @@ comment "gl needs the gst1-plugins-bad opengl library"
 
 config BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_HLS
 	bool "hls"
-	select BR2_PACKAGE_GNUTLS
+	select BR2_PACKAGE_NETTLE if !(BR2_PACKAGE_LIBGCRYPT || BR2_PACKAGE_OPENSSL)
 	help
 	  Fragmented streaming plugins
 

package/gstreamer1/gst1-plugins-bad/gst1-plugins-bad.mk

@@ -650,7 +650,19 @@ endif
 
 ifeq ($(BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_HLS),y)
 GST1_PLUGINS_BAD_CONF_OPTS += --enable-hls
-GST1_PLUGINS_BAD_DEPENDENCIES += gnutls
+
+ifeq ($(BR2_PACKAGE_NETTLE),y)
+GST1_PLUGINS_BAD_DEPENDENCIES += nettle
+GST1_PLUGINS_BAD_CONF_OPTS += --with-hls-crypto=nettle
+else ifeq ($(BR2_PACKAGE_LIBGCRYPT),y)
+GST1_PLUGINS_BAD_DEPENDENCIES += libgcrypt
+GST1_PLUGINS_BAD_CONF_OPTS += --with-hls-crypto=libgcrypt \
+	--with-libgcrypt-prefix=$(STAGING_DIR)/usr
+else
+GST1_PLUGINS_BAD_DEPENDENCIES += openssl
+GST1_PLUGINS_BAD_CONF_OPTS += --with-hls-crypto=openssl
+endif
+
 else
 GST1_PLUGINS_BAD_CONF_OPTS += --disable-hls
 endif