Introduce Alternate Toolchain gcc and binutils

Hostboot, OCC and potentially other packages are *VERY* sensitive to
GCC+binutils combinations (specially due to the use of libbfd to feed
the custom linker/loader script). That means that the default buildroot
toolchain can't be easily upgraded without risking hard-to-debug build
and runtime issues that might be caused by the change of the compiler +
binutils combination.

Address this by creating (yet another) GCC + Binutils host packages pair
that can be used, as an alternative to the one provided by buildroot.

Doing so would allow such packages to stay (indefinitely) using their
choice of gcc+binutils, while still allowing buildroot (and the Skiroot
environment) to evolve and use newer versions / releases.

Signed-off-by: Klaus Heinrich Kiwi <klaus@linux.vnet.ibm.com>
diff --git a/openpower/package/hostboot/Config.in b/openpower/package/hostboot/Config.in
index be08096..bbb7281 100644
--- a/openpower/package/hostboot/Config.in
+++ b/openpower/package/hostboot/Config.in
@@ -35,5 +35,13 @@
         help
             String used to define hw specific make config file
 
-endif
 
+config BR2_HOSTBOOT_USE_ALTERNATE_GCC
+		bool "use Alternate GCC to build hostboot"
+		default n
+		select BR2_PACKAGE_ALTERNATE_GCC
+		help
+		  Select to enable using an alternate version of GCC
+		  to build hostboot.
+
+endif