i2c: octeon_i2c: Misc fixes for ARM Octeon TX2 support

This patch fixes a few issues noticed, when testing this new driver on
ARM Octeon TX2 again. Here the details:

- Remove "common.h" header inclusion
- Use correct THP define on Octeon TX2
- Octeon TX2 uses the same compatible as Octeon TX. We can't distinguish
  both platforms this way. Remove the unused "cavium,thunder2-99xx-twsi"
  compatible and add a check to the Octeon TX2 specific
  "cavium,thunderx-i2c" so that the correct driver data is selected.
- Removed "struct pci_device_id" definition and U_BOOT_PCI_DEVICE()
  as its not needed for the PCI based probing on Octeon TX2

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Suneel Garapati <sgarapati@marvell.com>
Cc: Aaron Williams <awilliams@marvell.com>
Cc: Chandrakala Chavva <cchavva@marvell.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>