intel post-car: Increase stacktop alignment

Align top of stack to 8 bytes, value documented as FSP1.1 requirement.
Also fix some cases of uintptr_t casted to unsigned long.

Change-Id: I5bbd100eeb673417da205a2c2c3410fef1af61f0
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/17461
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/drivers/intel/fsp1_1/stack.c

@@ -35,14 +35,12 @@ void *setup_stack_and_mtrrs(void)
 	uint32_t max_mtrrs;
 	uint32_t num_mtrrs;
 	uint32_t *slot;
-	unsigned long top_of_stack;
 
 	/* Display the MTTRs */
 	soc_display_mtrrs();
 
 	/* Top of stack needs to be aligned to a 8-byte boundary. */
-	top_of_stack = romstage_ram_stack_top();
-	slot = (void *)top_of_stack;
+	slot = (void *)romstage_ram_stack_top();
 	num_mtrrs = 0;
 	max_mtrrs = soc_get_variable_mtrr_count(NULL);