omap3: igep0x00: Switch to the I2C driver model

omap3: igep0x00: Switch to the I2C driver model

When building with the igep00x0_defconfig, the following warning is shown:

  $ make -j $(nproc)
  ...
    LD      spl/u-boot-spl
    OBJCOPY spl/u-boot-spl-nodtb.bin
    SYM     spl/u-boot-spl.sym
    CAT     spl/u-boot-spl-dtb.bin
    COPY    spl/u-boot-spl.bin
    MKIMAGE MLO
  ===================== WARNING ======================
  This board does not use CONFIG_DM_I2C (Driver Model
  for I2C drivers). Please update the board to use
  CONFIG_DM_I2C before the v2022.04 release. Failure to
  update by the deadline may result in board removal.
  See doc/develop/driver-model/migration.rst for more info.
  ====================================================

The only reason why I2C is enabled for the IGEP boards is that the TWL4030
driver requires it.

But both the TWL4034 and the OMAP I2C controller drivers were converted to
the driver model by commits daa69ffe3d4d ("drivers: i2c: omap24xx_i2c:
adopt omap_i2c driver to driver model") and fb1b7712ad3f power: make most
tps drivers and the twl4030 driver compatible with DM_I2C") respectively.

So there's no reason anymore to keep using the I2C legacy API and instead
the DM_I2C option could just be enabled.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Enric Balletbo i Serra <eballetbo@gmail.com>