i2c-omap: FIFO handling support and broken hw workaround for i2c-omap

Based on an earlier patch from Nishant Menon:

- Transfers can use FIFO on FIFO capable devices
- Prevents errors for HSI2C if FIFO is not used
- Implemented errenous handling of STT-STP handling on SDP2430

Also merged in is a fix from Jaron Marini to fix occasional i2c
hang if OMAP_I2C_CON_STT remains asserted.

Signed-off-by: Jason P Marini <jason.marini@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>