[PATCH] I2C: Setting w83627hf fan divisor 128 fails.

Jarkko Lavinen provided patch to fix: "couldn't set the divisor 128
through fan1_div sysfs entry even though the chip supports it and
setting divisors 1..64 worked. This was due to POWER_TO_REG() only
checking 2's powers 0 till 5 but not 6."

This patch applies that fix to w83627hf and w83781d drivers.

Signed-off-by: Grant Coady <gcoady@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>