omap24xx_i2c: Handle OMAP5 like OMAP2,3,4

OMAP5 has 8b i2c data register field, like OMAP2, 3 and 4. Handle in the same
way. This fixes the following error on OMAP5:

  OMAP5430 EVM # mmc rescan
  timed out in wait_for_bb: I2C_STAT=1410
  twl6035: could not turn on LDO9.

Signed-off-by: Vincent Stehlé <v-stehle@ti.com>