mfd: lpc_ich: Use ALIGN_DOWN() to obtain the start of the SPI base range

Instead of open coding, use ALIGN_DOWN() for alignment.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231229145059.6138-1-ilpo.jarvinen@linux.intel.com


Signed-off-by: Lee Jones <lee@kernel.org>