package/qt6/qt6base: fix build when xcb support is enabled

Fixes:
ERROR: Feature "xcb": Forcing to "ON" breaks its condition:
QT_FEATURE_thread AND TARGET XCB::XCB AND TEST_xcb_syslibs AND QT_FEATURE_xkbcommon_x11
Condition values dump:
QT_FEATURE_thread = "ON"
TARGET XCB::XCB found
TEST_xcb_syslibs = "FALSE"
QT_FEATURE_xkbcommon_x11 not evaluated

The xcb feature is defined in [2].

According to [1] XCB::CURSOR is needed for xcb support.

[1] https://code.qt.io/cgit/qt/qtbase.git/tree/src/gui/configure.cmake?h=6.9.0#n522
[2] https://code.qt.io/cgit/qt/qtbase.git/tree/src/gui/configure.cmake?h=6.9.0#n1016

This bug was introduced in e634be8906bd64d6a9de1768204d0f03d8d8357a,
and fixes the build with the following defconfig:

 BR2_arm=y
 BR2_cortex_a9=y
 BR2_ARM_ENABLE_VFP=y
 BR2_TOOLCHAIN_EXTERNAL=y
 BR2_TOOLCHAIN_EXTERNAL_BOOTLIN=y
 BR2_TOOLCHAIN_EXTERNAL_BOOTLIN_ARMV7_EABIHF_MUSL_STABLE=y
 BR2_PACKAGE_QT6=y
 BR2_PACKAGE_QT6BASE_GUI=y
 BR2_PACKAGE_QT6BASE_XCB=y
 BR2_PACKAGE_XORG7=y

Signed-off-by: Roy Kollen Svendsen <roykollensvendsen@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>
(cherry picked from commit adff0d37ba9cd5f3bf6d1b0faa562a1e097a244b)
Signed-off-by: Thomas Perale <thomas.perale@mind.be>

package/qt6/qt6base/Config.in

@@ -61,6 +61,7 @@ config BR2_PACKAGE_QT6BASE_XCB
 	depends on BR2_PACKAGE_XORG7
 	select BR2_PACKAGE_XLIB_LIBX11
 	select BR2_PACKAGE_LIBXCB
+	select BR2_PACKAGE_XCB_UTIL_CURSOR
 	select BR2_PACKAGE_XCB_UTIL_IMAGE
 	select BR2_PACKAGE_XCB_UTIL_KEYSYMS
 	select BR2_PACKAGE_XCB_UTIL_RENDERUTIL

package/qt6/qt6base/qt6base.mk

@@ -211,6 +211,7 @@ QT6BASE_CONF_OPTS += \
 QT6BASE_DEPENDENCIES += \
 	libxcb \
 	libxkbcommon \
+	xcb-util-cursor \
 	xcb-util-wm \
 	xcb-util-image \
 	xcb-util-keysyms \