ASoC: wm_adsp: Log addresses as 8 digits in wm_adsp_buffer_populate

Increase the address value width in the debug log from 4 digits to
8 digits to allow for DSP cores with larger memory address ranges.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>