buildman: Add an option to use the full tool chain path

In some cases there may be multiple toolchains with the same name in the
path. Provide an option to use the full path in the CROSS_COMPILE
environment variable.

Note: Wolfgang mentioned that this is dangerous since in some cases there
may be other tools on the path that are needed. So this is set up as an
option, not the default. I will need test confirmation (i.e. that this
commit fixes a real problem) before merging it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Steve Rae <srae@broadcom.com>

tools/buildman/builder.py

@@ -175,7 +175,7 @@ class Builder:
 
     def __init__(self, toolchains, base_dir, git_dir, num_threads, num_jobs,
                  gnu_make='make', checkout=True, show_unknown=True, step=1,
-                 no_subdirs=False):
+                 no_subdirs=False, full_path=False):
         """Create a new Builder object
 
         Args:
@@ -189,6 +189,10 @@ class Builder:
                 This is used for testing.
             show_unknown: Show unknown boards (those not built) in summary
             step: 1 to process every commit, n to process every nth commit
+            no_subdirs: Don't create subdirectories when building current
+                source for a single board
+            full_path: Return the full path in CROSS_COMPILE and don't set
+                PATH
         """
         self.toolchains = toolchains
         self.base_dir = base_dir
@@ -215,6 +219,7 @@ class Builder:
         self.in_tree = False
         self._error_lines = 0
         self.no_subdirs = no_subdirs
+        self.full_path = full_path
 
         self.col = terminal.Color()