i2c: mlxbf: support lock mechanism

i2c: mlxbf: support lock mechanism

[ Upstream commit 86067ccfa1424a26491542d6f6d7546d40b61a10 ]

Linux is not the only entity using the BlueField I2C busses so
support a lock mechanism provided by hardware to avoid issues
when multiple entities are trying to access the same bus.

The lock is acquired whenever written explicitely or the lock
register is read. So make sure it is always released at the end
of a successful or failed transaction.

Fixes: b5b5b32081cd206b (i2c: mlxbf: I2C SMBus driver for Mellanox BlueField SoC)
Reviewed-by: Khalil Blaiech <kblaiech@nvidia.com>
Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>