lib/prog_loaders: use common ramstage_cache_invalid()

All current implementations of ramstage_cache_invalid() were just
resetting the system based on the RESET_ON_INVALID_RAMSTAGE_CACHE
Kconfig option. Move that behavior to a single implementation
within prog_loaders.c which removes duplication.

Change-Id: I67aae73f9e1305732f90d947fe57c5aaf66ada9e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/17184
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/cpu/intel/haswell/romstage.c

@@ -264,13 +264,3 @@ void asmlinkage romstage_after_car(void)
 	/* Load the ramstage. */
 	run_ramstage();
 }
-
-
-#if IS_ENABLED(CONFIG_CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM)
-void ramstage_cache_invalid(void)
-{
-#if CONFIG_RESET_ON_INVALID_RAMSTAGE_CACHE
-	reset_system();
-#endif
-}
-#endif