Do not include Makefile.base as 'DIRS' are not used here.
Also if 'all' target was to be used, there would be two rules creating
`$(BINDIR)/jerryscript.a`.
By default `Makefile.jerryscript` executes `libjerry` as it is the first
target.
Without this disabled `nanosleep()` is used, which isn't provided for
most our platforms (though the header `<time.h>` is).
Furthermore, that macro is only used in that instance throughout the
JerryScript codebase.
