crosstool-ng: Use same naming convention as internal toolchains

Use unknown for the vendor part of the tuple, and add $arch-linux- symlinks,
similar to how it's done for the internal toolchain, rather than using
buildroot_ctng and unknown symlinks.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

toolchain/toolchain-crosstool-ng/crosstool-ng.mk

@@ -201,8 +201,8 @@ CTNG_FIX_DOT_CONFIG_SED += s:^\# (CT_ARCH_$(CTNG_ENDIAN)) is not set:\1=y:;
 CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_ARCH_(32|64)).*:\# \2 is not set:;
 CTNG_FIX_DOT_CONFIG_SED += s:^\# (CT_ARCH_$(CTNG_BIT)) is not set:\1=y:;
 CTNG_FIX_DOT_CONFIG_SED += s:^\# (CT_ARCH_USE_MMU) is not set:\1=y:;
-CTNG_FIX_DOT_CONFIG_SED += s:^(CT_TARGET_VENDOR)=.*:\1="buildroot_ctng":;
-CTNG_FIX_DOT_CONFIG_SED += s:^(CT_TARGET_ALIAS)=.*:\1="$(REAL_GNU_TARGET_NAME)":;
+CTNG_FIX_DOT_CONFIG_SED += s:^(CT_TARGET_VENDOR)=.*:\1="unknown":;
+CTNG_FIX_DOT_CONFIG_SED += s:^(CT_TARGET_ALIAS)=.*:\1="$(GNU_TARGET_NAME)":;
 CTNG_FIX_DOT_CONFIG_SED += s:^(CT_CC_PKGVERSION)="(.*)":\1="crosstool-NG $(CTNG_VERSION) - buildroot $(BR2_VERSION_FULL)":;
 ifneq ($(call qstrip,$(BR2_PACKAGE_GDB_SERVER))$(call qstrip,$(BR2_PACKAGE_GDB_HOST)),)
 CTNG_FIX_DOT_CONFIG_SED += s:^(CT_DEBUG_gdb)=.*:\# \1 is not set:;