package/transmission: fix gtk dependencies

Buildroot commit 80793107a65d95f8dfd0317a726d3a737c78ef67 forgot to add
packages needed for gtk support:
https://github.com/transmission/transmission/blob/main/CMakeLists.txt#L40

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
[yann.morin.1998@free.fr:
  - don't add dependencies to C++ or wh-char, already global deps
  - propagate sync-4 dependency to comment
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit b600dbc3191409b52517686bf08aa1d08c31d96e)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/transmission/Config.in

@@ -37,11 +37,16 @@ config BR2_PACKAGE_TRANSMISSION_DAEMON
 
 config BR2_PACKAGE_TRANSMISSION_GTK
 	bool "transmission-gtk"
+	depends on !BR2_nios2 # gtkmm3
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4 # pangomm, libgtk3 -> pango -> harfbuzz -> gtkmm3
 	depends on BR2_PACKAGE_LIBGTK3 && BR2_SYSTEM_ENABLE_NLS
+	select BR2_PACKAGE_GTKMM3
 	help
 	  Install transmission GTK-based GUI interface.
 
-comment "transmission-gtk needs NLS enabled"
+comment "transmission-gtk needs libgtk3 and a toolchain with NLS enabled"
+	depends on !BR2_nios2
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4
 	depends on BR2_PACKAGE_LIBGTK3 && !BR2_SYSTEM_ENABLE_NLS
 endif
 

package/transmission/transmission.mk

@@ -74,7 +74,7 @@ endif
 
 ifeq ($(BR2_PACKAGE_TRANSMISSION_GTK),y)
 TRANSMISSION_CONF_OPTS += -DENABLE_GTK=ON
-TRANSMISSION_DEPENDENCIES += libgtk3
+TRANSMISSION_DEPENDENCIES += gtkmm3 libgtk3
 else
 TRANSMISSION_CONF_OPTS += -DENABLE_GTK=OFF
 endif