intel_adsp: ace20_lnl: Fix i2svss DT field initialization

This patch fixes i2svss field initialisation in Device Tree for LNL
platform. It fixes this bug: #482

Problem is observed only when using SSP_BLOB_VER_1_5 version.
Unfortunatelly this version is not tested in FW validation tests.

Signed-off-by: Jaroslaw Stelter <Jaroslaw.Stelter@intel.com>