net: dsa: lan9303: ensure chip reset and wait for READY status

net: dsa: lan9303: ensure chip reset and wait for READY status

Accessing device registers seems to be not reliable, the chip
revision is sometimes detected wrongly (0 instead of expected 1).

Ensure that the chip reset is performed via reset GPIO and then
wait for 'Device Ready' status in HW_CFG register before doing
any register initializations.

Cc: stable@vger.kernel.org
Fixes: a1292595e006 ("net: dsa: add new DSA switch driver for the SMSC-LAN9303")
Signed-off-by: Anatolij Gustschin <agust@denx.de>
[alex: reworked using read_poll_timeout()]
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/20241004113655.3436296-1-alexander.sverdlin@siemens.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>