litecross: always disable multilib, suppress lib64, etc. dir structures

multilib would not be usable without building multiple versions of
musl anyway, which we don't yet support, so enabling it does not make
sense. due to bugs in gcc's build system, even with multilib disabled,
multilib dir structures get used on 64-bit archs leading to target
libs being installed in /lib64 (or /libx32, etc.) under the sysroot,
rather than /lib. fix this by suppressing the variable that controls
it.

litecross/Makefile

@@ -14,12 +14,14 @@ XGCC = $(XGCC_DIR)/xgcc -B $(XGCC_DIR)
 
 -include config.mak
 
+MAKE += MULTILIB_OSDIRNAMES=
 MAKE += INFO_DEPS= infodir=
 MAKE += ac_cv_prog_lex_root=lex.yy.c
 
 FULL_TOOLCHAIN_CONFIG = $(TOOLCHAIN_CONFIG) \
 	--disable-werror \
 	--target=$(TARGET) --prefix= \
+	--libdir=/lib --disable-multilib \
 	--with-sysroot=$(SYSROOT) \
 	--with-build-sysroot='$$(LC_ROOT)/obj_sysroot' \
 	--enable-tls \