i2c: designware: Change from u32 to unsigned int for regmap_read() calls

regmap_read() API signature expects the caller to send "unsigned int"
type to return back the read value, but there are some occurrences of 'u32'
across i2c-designware-* files.

Change them to match the regmap_read() signature.

Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>