[crypto] Increase OTBN DMEM/IMEM

Increase the size of the OTBN DMEM from 4 KiB to 32 KiB (32768 bytes)
and the size of the IMEM from 8 KiB to 16 KiB (16384 bytes).

Signed-off-by: Andrea Caforio <[email protected]>

Author: andrea-caforio

hw/ip/otbn/data/otbn.hjson

@@ -748,14 +748,15 @@
       ]
     }
 
-    // Give IMEM and DMEM 16 KiB address space, each, to allow for easy expansion
+    // Give IMEM and DMEM 32 KiB address space, each, to allow for easy expansion
     // of the actual IMEM and DMEM sizes without changing the address map.
-    { skipto: "0x4000" }
+    { skipto: "0x8000" }
 
     // Imem size (given as `items` below) must be a power of two.
     { window: {
         name: "IMEM",
-        items: "2048", // 8 kB
+        // 16 KiB
+        items: "4096",
         swaccess: "rw",
         data-intg-passthru: "true",
         byte-write: "false",
@@ -773,12 +774,14 @@
       }
     }
 
-    { skipto: "0x8000" }
+    { skipto: "0x10000" }
 
     // Dmem size (given as `items` below) must be a power of two.
     { window: {
         name: "DMEM",
-        items: "768", // 3 kB visible over the bus (1 kB scratch)
+        // 32 KiB
+        // TODO: Define division into .bss and .scratchpad sections.
+        items: "8192",
         unusual: "true", // Needed to avoid an error because of the non-power-of-two size
         swaccess: "rw",
         data-intg-passthru: "true",