i2c: mvtwsi: Fix mvtwsi not working on sun6i and newer sunxi SoCs

i2c: mvtwsi: Fix mvtwsi not working on sun6i and newer sunxi SoCs

On sun6i and newer IFLG is a write-clear bit which is cleared by writing 1,
rather then a normal r/w bit which is cleared by writing 0.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
applied with fixing 3 checkpatch warnings
in drivers/i2c/mvtwsi.c:
WARNING: line over 80 characters
ERROR: code indent should use tabs where possible
WARNING: please, no spaces at the start of a line

Signed-off-by: Heiko Schocher <hs@denx.de>