Add option to oe-buildenv-internal script to change bitbake location.

Having bitbake inside the oe-core is annoying to some people. This commit
adds a second option to the oe-init-build-env script.

Run like this:

. ./oe-init-build-env ../build ../bitbake

for example. Without the second option, the old behavior is preserved.

(From OE-Core rev: 45510a0dd7a9321c29c5b21ac4053192f7ab9ad5)

Signed-off-by: Philip Balister <philip@balister.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/oe-buildenv-internal

@@ -54,7 +54,11 @@ else
 fi
 unset BDIR
 
-BITBAKEDIR="$OEROOT/bitbake$BBEXTRA/"
+if [ "x$2" = "x" ]; then
+    BITBAKEDIR="$OEROOT/bitbake$BBEXTRA/"
+else
+    BITBAKEDIR="$2"
+fi
 
 BITBAKEDIR=`readlink -f "$BITBAKEDIR"`
 BUILDDIR=`readlink -f "$BUILDDIR"`