bancha: leave space for the OpenTitan secure boot manifest

Bootable OpenTitan firwmare images have a manifest structure at offset
zero that identifies the entry point and that provides the signature
for doing secure boot. Leave space for the manifest by bumping the
instruction memory offset +0x380 (896) bytes.

Bypass-Presubmit-Reason: verified as part of topic

Change-Id: If36e70bdce23fb6306084d9a17d5f03baff92cc2

sdk/boards/bancha.json

diff --git a/sdk/boards/bancha.json b/sdk/boards/bancha.json
index bd1dca4..72678a3 100644
--- a/sdk/boards/bancha.json
+++ b/sdk/boards/bancha.json
@@ -50,7 +50,7 @@
         }
     },
     "instruction_memory": {
-        "start": 0x10000000,
+        "start": 0x10000380,
         "end": 0x10400000
     },
     "heap": {