ext: hal: nordic: Update nrfx to version 1.4.0

Updates nrfx to the recently released version. See
https://github.com/NordicSemiconductor/nrfx/blob/v1.4.0/CHANGELOG.md
for a list of changes that this version introduces.

Origin: nrfx
License: BSD 3-Clause
URL: https://github.com/NordicSemiconductor/nrfx/tree/v1.4.0


commit: 595e79f63f21224f6a42325095be9940a4a62ffb
Purpose: Provide peripheral drivers for Nordic SoCs
Maintained-by: External

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>