i2c: dw: Update the master_xfer callback name

In light of the recent updates to the i2c subsystem, ensure to use the
correct callback names. Specifically, replace '.master_xfer' with '.xfer'.

Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250217124709.3121848-2-Shyam-sundar.S-k@amd.com