sim-posix: align some sim copies of drivers to match real drivers
sim-posix: use real pios drivers whenever possible instead of copying
sim-posix: remove all unnecessary copies of pios drivers
sim-osx: remove all unnecessary copies of pios drivers
sim: align osx and posix sim driver variants wherever possible
sim-posix: misc makefile cleanup
sim-osx: use real pios drivers whenever possible instead of copying
sim makefiles: align makefiles between osx and posix sims
sim: provide missing definition of pios_com_debug_id
sim: provide weakly linked versions of external sim
pios tim: uint32_t -> uintptr_t
pios rtc: uint32_t -> uintptr_t
pios com: uint32_t -> uintptr_t

This change makes the code work for 64-bit compilations
as well as 32-bit (i.e. sim).

The lower drivers will be updated in separate commits
pios tcp/udp: uint32_t -> uintptr_t
pios usart: uint32_t -> uintptr_t
pios rfm22b_com: uint32_t -> uintptr_t
pios usb: uint32_t -> uintptr_t
pios com_msg: uint32_t -> uintptr_t
pios usb_rctx: uint32_t -> uintptr_t
pios can: uint32_t -> uintptr_t