i2c: rzv2m: Disable the operation of unit in case of error

The remove and suspend callbacks disable the operation of the unit.
Do the same in probe() in case of error.

While at it, introduce a helper function rzv2m_i2c_disable() for
disabling the operation of the unit and this function is shared
between probe error path, remove and suspend callbacks.

Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>