i2c-omap: Bug in reading the RXSTAT/TXSTAT values from the I2C_BUFFSTAT register

Fix bug in reading the I2C_BUFFSTAT register for getting byte count on RX/TX interrupt.

On Interrupt: I2C_STAT[RDR],
	read 'RXSTAT' from I2C_BUFFSTAT[8-13]
On Interrupt: I2C_STAT[XDR]
	read 'TXSTAT' from I2C_BUFFSTAT[0-5]

Signed-off-by: Jagadeesh Pakaravoor <j-pakaravoor@ti.com>
Signed-off-by: Moiz Sonasath <m-sonasath@ti.com>
Signed-off-by: Vikram pandita <vikram.pandita@ti.com>
[ben-linux@fluff.org: fixed mail format and added i2c-omap to subject]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>