Allows user to set (almost) any PWM frequency (#12638)

Marlin/Configuration_adv.h

Marlin/src/HAL/HAL_AVR/SanityCheck.h

Marlin/src/HAL/HAL_AVR/fastio_AVR.h

Marlin/src/inc/Conditionals_post.h

Marlin/src/module/planner.cpp

Marlin/src/module/temperature.cpp

Marlin/src/module/temperature.h

config/default/Configuration_adv.h

config/examples/3DFabXYZ/Migbot/Configuration_adv.h

config/examples/AlephObjects/TAZ4/Configuration_adv.h

config/examples/AliExpress/UM2pExt/Configuration_adv.h

config/examples/Anet/A2/Configuration_adv.h

config/examples/Anet/A2plus/Configuration_adv.h

config/examples/Anet/A6/Configuration_adv.h

config/examples/Anet/A8/Configuration_adv.h

config/examples/AnyCubic/i3/Configuration_adv.h

config/examples/ArmEd/Configuration_adv.h

config/examples/BIBO/TouchX/cyclops/Configuration_adv.h

config/examples/BIBO/TouchX/default/Configuration_adv.h

config/examples/BQ/Hephestos/Configuration_adv.h