kconfiglib: Update to 2259d353426f1

Update Kconfiglib to upstream revision 2259d353426f1 (+ local Zephyr
modifications) to get commit 2259d353426f1 ("Generalize is_menuconfig to
non-symbol items") in. It will be used by the menuconfig implementation.

Origin: https://github.com/zephyrproject-rtos/Kconfiglib/tree/zephyr

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
1 file changed