ACPICA: iASL: NHLT: Fix parsing undocumented bytes at the end of Endpoint Descriptor

ACPICA commit 961221a76814ffa0ecc92219ddf857579b0f7d54

Undocumented bytes at the end of Endpoint Descriptor can be present
independently of Linux-specific structures. Their size can also vary.

Link: https://github.com/acpica/acpica/commit/961221a7Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/acpi/actbl2.h

@@ -1685,10 +1685,6 @@ struct acpi_nhlt_linux_specific_data {
 	u8 device_port_id;
 };
 
-struct acpi_nhlt_linux_specific_data_b {
-	u8 specific_data[18];
-};
-
 /*******************************************************************************
  *
  * PCCT - Platform Communications Channel Table (ACPI 5.0)