ARM: tegra: rename colibri_t20 board/configuration/device-tree

In accordance with our other modules supported by U-Boot and as agreed
upon for Apalis/Colibri T30 get rid of the carrier board in the board/
configuration/device-tree naming.

While at it also bring the prompt more in line with our other products.

Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/tools/buildman/README b/tools/buildman/README
index cf7bf5c..e870d54 100644
--- a/tools/buildman/README
+++ b/tools/buildman/README
@@ -613,7 +613,7 @@
                  run_list_real                             1996    2000      +4
                  do_nandboot                                760     756      -4
                  do_mem_crc                                 168      68    -100
-            colibri_t20_iris:  all -9  rodata -29  text +20
+            colibri_t20    :  all -9  rodata -29  text +20
                u-boot: add: 1/0, grow: 2/-3 bytes: 140/-112 (28)
                  function                                   old     new   delta
                  hash_command                                80     160     +80