ext: hal: openisa: sync with updates for BLE SW LL

There are a couple of commits that are needed for
the BLE SW LL to function properly on the VEGABoard:
- TRNG entropy driver
- GenFSK radio enablement + configuration

As such, make sure that the commit in the manifest
points to the appropriate SHA in the hal/openisa
repo.

Signed-off-by: Alex Porosanu <alexandru.porosanu@nxp.com>