ptp: ptp_clockmatrix: use i2c_master_send for i2c write

The old code for i2c write would break on some controllers, which fails
at handling Repeated Start Condition. So we will just use i2c_master_send
to handle write in one transanction.

Changes since v1:
- Remove indentation change

Signed-off-by: Min Li <min.li.xe@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>