meta-google: gbmc: Add IGPS_MACHINE for 7xx

We generally use the eval board config for our 7xx platforms as it has
the sane defaults we usually depend on.

Change-Id: Ie136d7a83f39da66ade8b80814d8dcbbaefbc5ef
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/meta-google/conf/distro/gbmc.conf b/meta-google/conf/distro/gbmc.conf
index 89efcdc..0f5c6e8 100644
--- a/meta-google/conf/distro/gbmc.conf
+++ b/meta-google/conf/distro/gbmc.conf
@@ -39,7 +39,9 @@
 # Force the patches to not have any fuzz for gBMC
 ERROR_QA:append = " patch-fuzz"
 
-IGPS_MACHINE:npcm8xx = "Google"
+IGPS_MACHINE_DEFAULT = "EB"
+IGPS_MACHINE_DEFAULT:npcm8xx = "Google"
+IGPS_MACHINE ?= "${IGPS_MACHINE_DEFAULT}"
 
 # Remove dependencies on python3-core when using nftables
 PACKAGECONFIG:remove:pn-nftables = "python"