soc/amd/picasso: Up stack size to 40k for vboot hash buffer

Increasing the vboot hash buffer size greatly speeds up the SHA
calculations.  Going from a standard 4k buffer to a 36k buffer
takes ~150ms of the boot and resume time.

TEST=Build & boot see that boot time has decreased.
BRANCH=Zork
BUG=b:169217270 - Zork: SHA calculation in vboot takes too long

Signed-off-by: Martin Roth <martinroth@chromium.org>
Change-Id: Ibca868ad7be639c2a0ca1c4ba6d71123d8b83c92
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46902
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/picasso/memlayout_psp_verstage.ld

@@ -19,15 +19,15 @@
  * should be sufficient.  This is just for the function mapping the
  * actual stack.
  */
-#define PSP_VERSTAGE_TEMP_STACK_START	0x39000
+#define PSP_VERSTAGE_TEMP_STACK_START	0x32000
 #define PSP_VERSTAGE_TEMP_STACK_SIZE	4K
 
 /*
  * The top of the stack must be 4k aligned, so set the bottom as 4k aligned
  * and make the size a multiple of 4k
  */
-#define PSP_VERSTAGE_STACK_START	0x3B000
-#define PSP_VERSTAGE_STACK_SIZE		8K
+#define PSP_VERSTAGE_STACK_START	0x33000
+#define PSP_VERSTAGE_STACK_SIZE		40K
 
 ENTRY(_psp_vs_start)
 SECTIONS

src/soc/amd/picasso/psp_verstage/Makefile.inc

@@ -5,6 +5,9 @@ verstage-generic-ccopts += -I$(src)/vendorcode/amd/fsp/picasso/include
 verstage-generic-ccopts += -D__USER_SPACE__
 CPPFLAGS_common += -I$(VBOOT_SOURCE)/firmware/2lib/include/
 
+# This size should match the size in the linker script.
+CFLAGS_arm += -Wstack-usage=40960
+
 verstage-y += delay.c
 verstage-y += fch.c
 verstage-y += pmutil.c