Fix secure core plic config off-by-one error

Change-Id: I3fae156bbbdac82996079f82dd940d18b2331912

platforms/secure.repl

diff --git a/platforms/secure.repl b/platforms/secure.repl
index f677e7f..108b403 100644
--- a/platforms/secure.repl
+++ b/platforms/secure.repl
@@ -227,7 +227,7 @@
     // Bit 11 corresponds MEIP and bit 9 to SEIP.
     0 -> cpu0@11
     FatalAlert -> alert_handler@41
-    numberOfSources: 190
+    numberOfSources: 191
     numberOfContexts: 1
 
 // AES               [‘h4110_0000 - ‘h4110_0FFF)   4KB AES Control