nRF52 SDK 15.0 - Enable more than 1 interrupt

[trowbridgec]

Description

With the move from nRF52 SDK v14.2 to v15.0, the GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS setting was changed from a default of 4 to a default of 1 (the setting has now been renamed NRFX_GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS). This setting controls how many interrupts you can configure in your application and silently fails when you try to enable more than are configured. This issue was initially raised in #10949 by @anton-veretenenko, but we also ran into this problem while diagnosing why the mbed-os-example-lorawan example application stopped working with our nRF52840-based board once we moved to mbed-os-5.13.0 (the first release containing v15.0 of the nRF52 SDK).

This PR resets the default value for NRFX_GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS to 4 for both the nRF52840 and nRF52832.

Pull request type

[x] Fix
[ ] Refactor
[ ] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

Reviewers

Release Notes

[trowbridgec]

@maclobdell @ARMmbed/team-embeddedplanet

[ciarmcom]

@trowbridgec, thank you for your changes.
@ARMmbed/mbed-os-maintainers please review.

[bulislaw]

@linlingao can you review please

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 1
Build artifacts

[boraozgen]

Why is this set to another random number after which it fails silently rather than solving it properly? This should fail with an assert in case more InterruptIns are defined than configured.