vendorcode/amd/pi: Fix building with clang

Change-Id: I82913de07acc13af2f5f2c67853e112fb3c66319
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63048
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/vendorcode/amd/pi/Makefile.inc b/src/vendorcode/amd/pi/Makefile.inc
index 75de398..9b4659e 100644
--- a/src/vendorcode/amd/pi/Makefile.inc
+++ b/src/vendorcode/amd/pi/Makefile.inc
@@ -62,6 +62,7 @@
 AGESA_INC += -I$(VBOOT_SOURCE)/firmware/include
 
 AGESA_CFLAGS += -march=amdfam10 -mno-3dnow
+AGESA_CFLAGS += -Wno-pragma-pack
 AGESA_CFLAGS += -fno-strict-aliasing -D__LIBAGESA__
 CFLAGS_x86_32 += $(AGESA_CFLAGS)
 CFLAGS_x86_64 += $(AGESA_CFLAGS)