dtoc: add support to scan drivers

dtoc: add support to scan drivers

Currently dtoc scans dtbs to convert them to struct platdata and
to generate U_BOOT_DEVICE entries. These entries need to be filled
with the driver name, but at this moment the information used is the
compatible name present in the dtb. This causes that only nodes with
a compatible name that matches a driver name generate a working
entry.

In order to improve this behaviour, this patch adds to dtoc the
capability of scan drivers source code to generate a list of valid driver
names and aliases. This allows to generate U_BOOT_DEVICE entries using
valid driver names and rise a warning in the case a name is not valid.

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Open files in utf-8 mode:
Signed-off-by: Simon Glass <sjg@chromium.org>