Add build rules for HPS demo on flash

Change-Id: Ib55450e63caffca21e55b8ab15cc82abee7dc4c2

sw/device/examples/demo_hps_live/BUILD

diff --git a/sw/device/examples/demo_hps_live/BUILD b/sw/device/examples/demo_hps_live/BUILD
index e8b2bdf..cbe8e37 100644
--- a/sw/device/examples/demo_hps_live/BUILD
+++ b/sw/device/examples/demo_hps_live/BUILD
@@ -7,6 +7,7 @@
     "//rules:matcha.bzl",
     "ASIC_CORE_TARGETS",
     "NEXUS_CORE_TARGETS",
+    "matcha_extflash_tar",
     "sec_flash_binary",
     "smc_flash_binary",
 )
@@ -73,3 +74,14 @@
         ],
     }),
 )
+
+matcha_extflash_tar(
+    name = "hps_demo_asic_extflash",
+    sc_binary = ":hps_demo_asic_bin",
+)
+
+matcha_extflash_tar(
+    name = "hps_demo_fpga_nexus_extflash",
+    sc_binary = ":hps_demo_fpga_nexus_bin",
+)
+