[PATCH] docker.rst: Reword slightly around "buildx"

[Tom Rini]

Try and be slightly clearer about what "buildx" is, and how to install
it.

Signed-off-by: Tom Rini <trini at konsulko.com>
---
I rephrased this slightly to try and be clearer as if you're using the
docker.io provided packages you need to just install the plugin.

Cc: Simon Glass <sjg at chromium.org>
---
 doc/build/docker.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/build/docker.rst b/doc/build/docker.rst
index 5896dd5ac4a6..81b394597ffb 100644
--- a/doc/build/docker.rst
+++ b/doc/build/docker.rst
@@ -4,8 +4,8 @@ GitLab CI / U-Boot runner container
 In order to have a reproducible and portable build environment for CI we use a container for building in.  This means that developers can also reproduce the CI environment, to a large degree at least, locally.  This file is located in the tools/docker directory.
 
 The docker image supports both amd64 and arm64. Ensure that the
-'docker-buildx' Debian package is installed (or the equivalent on another
-distribution).
+`buildx` Docker CLI plugin is installed. This is often available in your
+distribution via the 'docker-buildx' or 'docker-buildx-plugin' package.
 
 You will need a multi-platform container, otherwise this error is shown::
 
-- 
2.43.0