common: fit: Add weak board_fit_config_name_match

Several architectures had a default board_fit_config_name_match already;
this provides a generic weak version. We default to rejecting all configs.
This will use the FIT's default config, instead of the first config. This
may result in boot failures if there are multiple configurations and the
first config is *not* the default.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
diff --git a/common/common_fit.c b/common/common_fit.c
index 219674d..cde2dc4 100644
--- a/common/common_fit.c
+++ b/common/common_fit.c
@@ -22,6 +22,11 @@
 	return fdt32_to_cpu(*cell);
 }
 
+__weak int board_fit_config_name_match(const char *name)
+{
+	return -EINVAL;
+}
+
 /*
  * Iterate over all /configurations subnodes and call a platform specific
  * function to find the matching configuration.