reintroduce input capture filter

[AlkaMotors]

No description provided.

[tridge]

great to see the input filtering!
some of the new targets don't build, for example AM32_FLYWOO_F4A_F421 fails with:

Mcu/f421/Src/phaseouts.c: In function 'comStep':
Mcu/f421/Src/phaseouts.c:332:24: error: 'PHASE_C_COMP' undeclared (first use in this function)
  332 |         CMP->ctrlsts = PHASE_C_COMP;
      |                        ^~~~~~~~~~~~
Mcu/f421/Src/phaseouts.c:339:24: error: 'PHASE_A_COMP' undeclared (first use in this function)
  339 |         CMP->ctrlsts = PHASE_A_COMP;
      |                        ^~~~~~~~~~~~
Mcu/f421/Src/phaseouts.c:346:24: error: 'PHASE_B_COMP' undeclared (first use in this function)
  346 |         CMP->ctrlsts = PHASE_B_COMP;
      |                        ^~~~~~~~~~~~

you can see this in the CI build tests
also, a minor thing, it is a good idea to use a branch other than 'main' for PRs, for example 'pr-input-filter' would be good, makes it easier to track

[AlkaMotors]

Whats wrong with these targets? It builds in Keil. The hardware group is defined. Edit. Oh the name om Flywoos target starts with am32. Does this double name cause problems. Ill check

[tridge]

Whats wrong with these targets?

I've put a branch here with fixes to the issues:
https://github.com/tridge/AM32/commits/alka-main-fixes/
one problem was an incorrect file name, another was due to the 12 character limit