soc/intel/apollolake: correct comment to reference top of CAR

The memory provided to MemoryInit() for its own usage is at the
top of the CAR region.

Change-Id: I8685b5ab138182e24123b14cac6f7b32e5e784d2
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/13957
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Andrey Petrov <andrey.petrov@intel.com>

src/soc/intel/apollolake/romstage.c

@@ -142,7 +142,7 @@ void platform_fsp_memory_init_params_cb(struct FSPM_UPD *mupd)
 	mupd->FspmConfig.FitTablePtr = read32((void*) FIT_POINTER);
 	/* Reserve enough memory under TOLUD to save CBMEM header */
 	mupd->FspmArchUpd.BootLoaderTolumSize = cbmem_overhead_size();
-	/* Let FSPM use memory right at the bottom of CAR */
+	/* Let FSPM use memory right at the top of CAR */
 	/* TODO: Add checks to see if we collide with other areas */
 	mupd->FspmArchUpd.StackBase = _car_region_end - CONFIG_FSPM_STACK_SIZE;
 	mupd->FspmArchUpd.StackSize = CONFIG_FSPM_STACK_SIZE;