Bluetooth: Controller: Use CMSIS NVIC APIs directly

Convert driver to use the CMSIS NVIC APIs rather than the internal
ones so we can remove them in the future.

Change-Id: Ib9fe696e8d5e55f60865d3fd958a035135ce517a
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
3 files changed