Avoid recurvise variable expansion error for wasm32-embedded

rtl/embedded/Makefile

@@ -1058,7 +1058,7 @@ $(error No CPUs enabled for given SUBARCH, pass either a SUBARCH or set CPU_UNIT
 endif
 endif
 ifeq ($(ARCH),wasm32)
-CPU_SPECIFIC_COMMON_UNITS=$(filter-out $(LINEINFOUNIT), $(CPU_SPECIFIC_COMMON_UNITS))
+CPU_SPECIFIC_COMMON_UNITS:=$(filter-out $(LINEINFOUNIT), $(CPU_SPECIFIC_COMMON_UNITS))
 endif
 OBJPASDIR=$(RTL)/objpas
 ifeq ($(CPU_OS_TARGET),i386-embedded)

rtl/embedded/Makefile.fpc

@@ -251,7 +251,7 @@ endif
 endif
 
 ifeq ($(ARCH),wasm32)
-CPU_SPECIFIC_COMMON_UNITS=$(filter-out $(LINEINFOUNIT), $(CPU_SPECIFIC_COMMON_UNITS))
+CPU_SPECIFIC_COMMON_UNITS:=$(filter-out $(LINEINFOUNIT), $(CPU_SPECIFIC_COMMON_UNITS))
 # lineinfo
 endif