sencha: track location of boot_rom.elf

Build changes moved the artifact; update the expected pathname.

Change-Id: If27ccfcee09d129b042e2e6ec10981d00ac92403
diff --git a/sencha.resc b/sencha.resc
index b3ed67c..2dd0624 100644
--- a/sencha.resc
+++ b/sencha.resc
@@ -50,7 +50,7 @@
 uart5-analyzer TimestampFormat None
 
 # Load the boot rom into the 32k rom at 0x8000 (useVirtualAddress = false, allowLoadsOnlyToMemory = true)
-sysbus LoadELF @out/matcha/hw/boot_rom.elf false true cpu0
+sysbus LoadELF @out/sencha/hw/boot_rom.elf false true cpu0
 
 # Start cpu0 at the bootrom reset vector, which is stored immediately after the
 # bootrom interrupt vector table at 0x8080.