Always set RTLCONSTSUNIT to rtlconsts, if FPC_DOTTEDUNITS is not defined, as OS specific changes are parsed after

rtl/inc/Makefile.rtl

@@ -437,9 +437,7 @@ PROFILEUNIT=profile
 RASPI2UNIT=raspi2
 RASPI3UNIT=raspi3
 RASPIUARTUNIT=raspiuart
-ifeq ($(RTLCONSTSUNIT),)
-  RTLCONSTSUNIT=rtlconsts
-endif
+RTLCONSTSUNIT=rtlconsts
 SAM3X8EUNIT=sam3x8e
 SAMD51P19AUNIT=samd51p19a
 SC32442BUNIT=sc32442b