qt5charts: fix qt5base widgets/gui selection

qt5charts: fix qt5base widgets/gui selection

Selection of BR2_PACKAGE_QT5BASE_WIDGETS needs BR2_PACKAGE_QT5BASE_GUI too.

Fixes qt5base configure failure ([1]):

  ERROR: Feature 'widgets' was enabled, but the pre-condition 'features.gui' failed.
[1] http://autobuild.buildroot.net/results/69c4385b2fd484d16f749b4cde6967f5cabea8b2

and buildroot warning:

  warning: (... && BR2_PACKAGE_QT5CHARTS && ...) selects BR2_PACKAGE_QT5BASE_WIDGETS
  which has unmet direct dependencies (BR2_PACKAGE_QT5 && BR2_PACKAGE_QT5BASE && BR2_PACKAGE_QT5BASE_GUI)

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Acked-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>