soc: intel_adsp/hda: fix range checking

intel_adsp_hda_set_buffer() asserts when the HDA buffer is
outside of RAM space. However, it uses CONFIG_SRAM_SIZE as
if it is bytes. In reality, CONFIG_SRAM_SIZE is in KB so
we need to multiply it by 1024, or simply use marco KB().

Fixes #74250

Signed-off-by: Daniel Leung <daniel.leung@intel.com>