Replace the Radiotap parser platform.h file with use of helper functions
from utils/common.h to avoid compiler issues with the updated design and
getting pointers to members of packet structs.
Silence the warning about _next_bitmap assignment. This pointer is
dereferenced only with operations that are safe for unaligned access, so
the compiler warning is not helpful here.
__packed might not be defined in this context, so use STRUCT_PACKED from
utils/common.h.
Fixes: e6ac269433 ("radiotap: Update radiotap parser")
Signed-off-by: Jouni Malinen <j@w1.fi>