bluetooth: controller: openisa/RV32M1: add HAL for LPTMR & GenFSK

This commit adds the HAL layer needed for the BLE controller
LL on RV32M1 SoCs on OpenISA boards. Specifically, the controller
makes use of the the GenFSK and LPTMR IP blocks.

Signed-off-by: George Stefan <george.stefan@nxp.com>
Signed-off-by: Radu Alexe <radu.alexe@nxp.com>
Signed-off-by: Ionut Ursescu <ionut.ursescu@nxp.com>