windows: Cleanup makefile

The BSD stuff is a copy from the unix makefile but at least there it
makes some sense, a windows makefile on BSD doesn't.
The -lmman flag is probably for mmap functions but there is no other build
support for it on windows so just that flag won't cut it anyway.

windows/Makefile

@@ -47,12 +47,8 @@ SRC_C += lib/mp-readline/readline.c
 else ifeq ($(MICROPY_USE_READLINE),2)
 CFLAGS_MOD += -DMICROPY_USE_READLINE=2
 LDFLAGS_MOD += -lreadline
-# the following is needed for BSD
-#LDFLAGS_MOD += -ltermcap
 endif
 
 LIB += -lws2_32
-#LIB += -lmman
 
 include ../py/mkrules.mk
-