imx6: icorem6_rqs: Add I2C support

imx6: icorem6_rqs: Add I2C support

Add I2C support for Engicam i.CoreM6 RQS modules.

icorem6qdl-rqs> i2c bus
Bus 0:  i2c@021a0000
Bus 1:  i2c@021a4000
Bus 2:  i2c@021a8000
icorem6qdl-rqs> i2c dev 0
Setting bus to 0
icorem6qdl-rqs> i2c speed 100000
Setting bus speed to 100000 Hz
icorem6qdl-rqs> i2c probe
Valid chip addresses: 4F
icorem6qdl-rqs> i2c md 4F 0xff
00ff: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
icorem6qdl-rqs> i2c bus
Bus 0:  i2c@021a0000  (active 0)
   4f: generic_4f, offset len 1, flags 0
Bus 1:  i2c@021a4000
Bus 2:  i2c@021a8000

Cc: Stefano Babic <sbabic@denx.de>
Cc: Matteo Lisi <matteo.lisi@engicam.com>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>