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/include/program_loading.h

@@ -167,9 +167,6 @@ void run_romstage(void);
 /* Run ramstage from romstage. */
 void run_ramstage(void);
 
-/* Called when the stage cache couldn't load ramstage on resume. */
-void ramstage_cache_invalid(void);
-
 /* Determine where stack for ramstage loader is located. */
 enum { ROMSTAGE_STACK_CBMEM, ROMSTAGE_STACK_LOW_MEM };
 uintptr_t romstage_ram_stack_base(size_t size, int src);