firmware: turris-mox-rwtm: show message about HWRNG registration

firmware: turris-mox-rwtm: show message about HWRNG registration

[ Upstream commit fae20160992269431507708fb74c1fd9f3c309c1 ]

Currently it is hard to determinate if on Armada 3720 device is HWRNG
by running kernel accessible or not. So print information message into
dmesg when HWRNG is available and registration was successful.

Fixes: 389711b37493 ("firmware: Add Turris Mox rWTM firmware driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>