Revert 12302 NVIC SPI Priority

[ctzsnooze]

This PR reverts a part of PR#12302 from Feb 6, by @hydra - the bit that changed SPI priority.

Unfortunately it seemed to badly affect some F411 boards.

For example, the NOX F411, with GPS and Softserial would randomly lock up, and fall out of the sky with 4.5. Additionally it didn't have the loop time stability I saw in the past. The only way to stop it locking up was to disable the OSD entirely.

This PR brings the old NOX board back to life, it now is rock solid stable again, even with OSD, GPS, new Angle and Horizon code. soft serial, all active.

This PR has been checked with several SX1280 ELRS SPI boards and does not appear to adversely affect link reliability.

[github-actions]

Do you want to test this code? Here you have an automated build:
Assets
WARNING: It may be unstable. Use only for testing! See: https://www.youtube.com/watch?v=I1uN9CN30gw for instructions for unified targets!

[blckmn]

Good stuff with the testing and perseverance to find this!

[ctzsnooze]

Difference in Cycletime stability - left without, right with the fix.
On right, motors were spinning and I had the new Angle/Horizon PR active. On the left, motors were not spinning, and code was just master. It locked up soon after this log.
Main benefit is that the FC doesn't lockup mid-flight now.

[freasy]

Makes total sense to revert this! Good find!

[blckmn]

AUTOMERGE: (FAIL)

• github identifies PR as mergeable -> FAIL
• assigned to a milestone -> PASS
• cooling off period lapsed -> PASS
• commit count less or equal to three -> PASS
• Don't merge label NOT found -> PASS
• at least one RN: label found -> PASS
• Tested label found -> FAIL
• assigned to an approver -> PASS
• approver count at least three -> FAIL