toolchain: introduce HOST_DIR option

Allow the user to define HOST_DIR in the config menu.

This way when building an internal toolchain a separate (maybe shared)
output directory may be defined and the toolchain can be used by
multiple users and/or projects.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

Config.in

@@ -72,6 +72,16 @@ config BR2_DL_DIR
 
 	  The default is $(TOPDIR)/dl
 
+config BR2_HOST_DIR
+	string "Host dir"
+	default "$(BASE_DIR)/host"
+	help
+	  Directory to store all the binary files that are built for the host.
+	  This includes the cross compilation toolchain when building the
+	  internal buildroot toolchain.
+
+	  The default is $(BASE_DIR)/host
+
 menu "Mirrors and Download locations"
 
 config BR2_PRIMARY_SITE

Makefile

@@ -274,8 +274,8 @@ TAR_OPTIONS=$(call qstrip,$(BR2_TAR_OPTIONS)) -xf
 
 GNU_TARGET_SUFFIX:=-$(call qstrip,$(BR2_GNU_TARGET_SUFFIX))
 
-# packages compiled for the host goes here
-HOST_DIR:=$(BASE_DIR)/host
+# packages compiled for the host go here
+HOST_DIR:=$(call qstrip,$(BR2_HOST_DIR))
 
 # stamp (dependency) files go here
 STAMP_DIR:=$(BASE_DIR)/stamps