lib: remove assets infrastructure

Now that only CBFS access is supported for finding resources
within the boot media the assets infrastructure can be removed.
Remove it.

BUG=chromium:445938
BRANCH=None
TEST=Built and ran on glados.

Change-Id: I383fd6579280cf9cfe5a18c2851baf74cad004e9
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/12690
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/arch/x86/boot.c b/src/arch/x86/boot.c
index 7eb87fb..bf9a02b 100644
--- a/src/arch/x86/boot.c
+++ b/src/arch/x86/boot.c
@@ -184,7 +184,7 @@
 
 static void try_payload(struct prog *prog)
 {
-	if (prog_type(prog) == ASSET_PAYLOAD) {
+	if (prog_type(prog) == PROG_PAYLOAD) {
 		if (IS_ENABLED(CONFIG_RELOCATABLE_RAMSTAGE))
 			jmp_payload_no_bounce_buffer(prog_entry(prog));
 		else