nexus sim: track move of timer_smc_sw irq

Bug: 295534548

Change-Id: I9fafd66c210e51a1dcb96ad39edf002d688be14a

platforms/nexus_smc.repl

diff --git a/platforms/nexus_smc.repl b/platforms/nexus_smc.repl
index 109a99e..4ff315e 100644
--- a/platforms/nexus_smc.repl
+++ b/platforms/nexus_smc.repl
@@ -29,7 +29,7 @@
 // Timer for Cantrip software timer service.
 timer_smc_sw: @ sysbus 0x54011000
     frequency: 2500000
-    IRQ -> smc_plic@39
+    IRQ -> smc_plic@38
 
 sysbus:
     init: