commands: drvinfo: Make locally used function static ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drvlist: factor the driver list out of 'devinfo' ...

The command 'devinfo' was first spitting out all devices, and then
also all drivers. This patch separates them into two commands,
'devinfo' as before, and also the new command 'drvinfo'

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>