console: Add format-checking __printf() to die()

Code changes are necessary because `-Wformat` warns about empty
format strings by default.

Change-Id: Ic8021b70f4cd4875b06f196f88b84940c9a79fe0
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75147
Reviewed-by: Jérémy Compostella <jeremy.compostella@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/include/console/console.h

@@ -18,7 +18,7 @@ void mainboard_post(u8 value);
 void arch_post_code(u8 value);
 void soc_post_code(uint8_t value);
 
-void __noreturn die(const char *fmt, ...);
+void __noreturn __printf(1, 2) die(const char *fmt, ...);
 #define die_with_post_code(value, fmt, ...) \
 	do { post_code(value); die(fmt, ##__VA_ARGS__); } while (0)