loader: add driver list as parameter in loader_open_render_node_platform_device()

loader: add driver list as parameter in loader_open_render_node_platform_device()

In a later commit in this series, we'll need to open the first supported
render-only platform device that we can find.

In order to avoid calling loader_open_render_node_platform_device()
multiple times (what is quite expensive), change this function to take a
driver list (instead of a single driver name) as parameter.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24825>