soc/amd/glinda: Update PSP MBOX offset in Kconfig

Glinda SoC PSP MBOX offset is 0x10970 & hence update the same in Kconfig

TEST=Tested with Birman Plus and it solved the issue for psp timeout

Before:
[DEBUG] PSP: Notify SMM info... error: PSP command timeout

After:
[DEBUG] PSP: Notify SMM info... OK

Change-Id: I328959513228fe0f9e78070eb6b302ef89857b42
Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85627
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/glinda/Kconfig

@@ -380,6 +380,10 @@ config PSP_VERSTAGE_SIGNING_TOKEN
 	help
 	  Add psp_verstage signature token to the build & PSP Directory Table
 
+config PSPV2_MBOX_CMD_OFFSET
+	hex
+	default 0x10970
+
 endmenu
 
 config VBOOT