i2c: sirf: retry 3 times as sometimes we get random noack and timeout

let i2c core retry 3 times as sometimes we get random noack and timeout
even when we access an existing i2c client.

Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>