i3c: ast2600: fix register setting for 545 ohm pullups

The 2k register setting is zero, OR-ing it in doesn't parallel the 2k
and 750 ohm pullups. We need a separate value for the 545 ohm setting.

Reported-by: Lukwinski Zbigniew <zbigniew.lukwinski@linux.intel.com>
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://lore.kernel.org/r/20230428001849.1775559-1-jk@codeconstruct.com.au


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>