soc/amd/stoneyridge: Remove unused psp.h

psp.h was first included when Stoney Ridge began loading the first
SMU firmware.  That step was later moved from bootblock to romstage.

Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Change-Id: Id646390ce377143d09455f797de1b149dbb615b5
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48797
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/stoneyridge/bootblock.c

@@ -15,7 +15,6 @@
 #include <soc/pci_devs.h>
 #include <soc/cpu.h>
 #include <soc/southbridge.h>
-#include <amdblocks/psp.h>
 #include <timestamp.h>
 #include <halt.h>