linux-firmware: New minor DMC release for Skylake - ver1_18

linux-firmware: New minor DMC release for Skylake - ver1_18

Following additions:
1. No changes to the FW program itself
2. CSS header size field was fixed
3. DMCheader length field is mentioned in dwords instead of bytes
4. Date field is fixed in header.
4. Fixed the DMC Header.HeaderLen issue. The HeaderLen is specified in bytes instead of dwords.
6. DC 5 and 6 count locations are in the below mentioned offsets - same as ver1.16
DC3_DC5_COUNT                  80030
DC5_DC6_COUNT                  8002C

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>