i2c: amd-mp2: Remove unused macro

Remove unused work_amd_i2c_common() macro.

Signed-off-by: Richard Neumann <mail@richard-neumann.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>