Add a level 2 interrupt controller for the RV32M1 SoC. This uses the
INTMUX peripheral.
As a first customer, convert the timer driver over to using this,
adding nodes for the LPTMR peripherals. This lets users select the
timer instance they want to use, and what intmux channel they want to
route its interrupt to, using DT overlays.
Signed-off-by: Marti Bolivar <marti@foundries.io>
Signed-off-by: Mike Scott <mike@foundries.io>
Marti Bolivar