xtensa: cavs: fix linker warnings on cAVS 2.0 and 2.5

Add the missing .cached section on cAVS 2.0 and 2.5 to fix
compiler warnings.

Signed-off-by: Guennadi Liakhovetski <[email protected]>

Author: lyakh

soc/xtensa/intel_adsp/cavs_v20/linker.ld

@@ -440,6 +440,10 @@ SECTIONS
     *(.gnu.linkonce.lit4.*)
     _lit4_end = ABSOLUTE(.);
   } >ram :ram_phdr
+  .cached :
+  {
+    *(.cached .cached.*)
+  } >ram :ram_phdr
 #include <linker/common-ram.ld>
 
   .bss (NOLOAD) : ALIGN(4096)

soc/xtensa/intel_adsp/cavs_v25/linker.ld

@@ -485,6 +485,10 @@ SECTIONS
     *(.gnu.linkonce.lit4.*)
     _lit4_end = ABSOLUTE(.);
   } >ram :ram_phdr
+  .cached :
+  {
+    *(.cached .cached.*)
+  } >ram :ram_phdr
 #include <linker/common-ram.ld>
 
   .AltBootManifest : ALIGN(8)