ASoC: samsung: i2s: Request memory region in driver probe()

The memory mapped registers region is common for both DAIs so request
it in the I2S platform device driver's probe for the platform device
corresponding to the primary DAI, rather than in the ASoC DAI's probe
callback. While at it switch to devm_ioremap_resource(). This also
drops the hard coded (0x100) register region size in the driver.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>