i2c: designware: Global register definitions

i2c: designware: Global register definitions

Moving the register definitions to a global header file
include/linux/designware_i2c.h. That removes the need to
duplicate them in the adaptation layers for this driver
outside of drivers/i2c/busses/. There is at least one of
those in drivers/gpu/drm/xe/xe_i2c.c.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://patch.msgid.link/20260811121008.1493015-2-heikki.krogerus@linux.intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 2ab2fb31411a494e4579dfacda986a2672f80e65)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>