Previously, --flash-mmu-page-size was only passed when the configured
MMU page size was not 64KB. This caused an issue for targets with a
configurable MMU page size whose non-64KB size is the actual default.
Remove the 64KB exclusion and always pass the argument for all targets,
including those without a configurable MMU page size. Since ESP-IDF now
always provides the value, esptool can also use it to change the
default MMU page size.
This changes how available ports are detected. It removes code duplication
for MacOS filtering which already is in esptool and prepares for port
prioritization to be used from esptool.