- Add ZMK_KSCAN_MATRIX_POLLING config flag to Kconfig
- Update matrix driver code to use the above flag to conditionally add the handling code for polling operations.
* Especially for splits, we need the ability to
unpair all paired devices as sledgehammer
if we need to "reset things", and doing so via
keymaps isn't suitable.
* Allows shields to define a collection of key
positions that if all held 2 seconds after
startup, will unpair all existing pairs for the
device.
* Basic Clueboard Californai Macropad shield definition.
* New "direct" KSCAN driver that supports non-matrix direct
wiring for switches, needed for macropad that doesn't have
a matrix at all.
* Some renames for existing KSCAN GPIO driver to make the implied
"matrix" part explicit.