buildman: Drop mention of old architectures

Support for some architectures has been removed since buildman was first
written. Also all toolchains are now available at kernel.org so we don't
need the links, except for arc where the kernel.org toolchain fails to
build all boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/buildman.rst b/tools/buildman/buildman.rst
index 4851a64..2a7593d 100644
--- a/tools/buildman/buildman.rst
+++ b/tools/buildman/buildman.rst
@@ -202,8 +202,6 @@
    riscv = riscv32
    sh = sh4
    x86: i386
-   blackfin: bfin
-   openrisc: or1k
 
 
    This selects the available toolchain paths. Add the base directory for
@@ -480,22 +478,13 @@
    For those not available from kernel.org, download from the following links:
 
    - `Arc Toolchain`_
-   - `Blackfin Toolchain`_
-   - `Nios2 Toolchain`_
-   - `SH Toolchain`_
-
-   Note openrisc kernel.org toolchain is out of date. Download the latest one
-   from `OpenRISC Toolchains`_, e.g. `OpenRISC 4.8.1`_.
 
    Buildman should now be set up to use your new toolchain.
 
    At the time of writing, U-Boot has these architectures:
 
-      arc, arm, blackfin, m68k, microblaze, mips, nios2, openrisc
-      powerpc, sandbox, sh, sparc, x86
+      arc, arm, m68k, microblaze, mips, nios2, powerpc, sandbox, sh, x86, xtensa
 
-   Of these, only arc is not available at kernel.org.
-
 
 How to run it
 -------------
@@ -1286,11 +1275,6 @@
 way around.
 
 .. _`Arc Toolchain`: https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/releases/download/arc-2021.03-release/arc_gnu_2021.03_prebuilt_elf32_le_linux_install.tar.gz
-.. _`Blackfin Toolchain`: http://sourceforge.net/projects/adi-toolchain/files/blackfin-toolchain-elf-gcc-4.5-2014R1_45-RC2.x86_64.tar.bz2
-.. _`Nios2 Toolchain`: http://sourcery.mentor.com/public/gnu_toolchain/nios2-linux-gnu/sourceryg++-2015.11-27-nios2-linux-gnu-i686-pc-linux-gnu.tar.bz2
-.. _`SH Toolchain`: http://sourcery.mentor.com/public/gnu_toolchain/sh-linux-gnu/renesas-4.4-200-sh-linux-gnu-i686-pc-linux-gnu.tar.bz2
-.. _`OpenRISC Toolchains`: http://opencores.org/or1k/OpenRISC_GNU_tool_chain#Prebuilt_versions
-.. _`OpenRISC 4.8.1`: ftp://ocuser:ocuser@openrisc.opencores.org/toolchain/gcc-or1k-elf-4.8.1-x86.tar.bz2
 
 .. sectionauthor:: Simon Glass
 .. sectionauthor:: Copyright (c) 2013 The Chromium OS Authors.