[ot] hw/riscv: ot_earlgrey: Connect alert escalation severities

Connects GPIO signals for the four different escalation severities of
OpenTitan Earlgrey's Alert handler.

For now, escalation signal 3 (phase 3) connects to the pwrmgr, where it
causes a shutdown as is the default in Darjeeling. In reality, the alert
handler should cause a reset in phase 3 and populate the rstmgr's
`reset_info` accordingly, but this requires additional work in other
blocks, and as such we simply leave this connected to the pwrmgr
shutdown for now to match Darjeeling's functionality.

Signed-off-by: Alex Jones <alex.jones@lowrisc.org>

Author: AlexJones0

hw/riscv/ot_earlgrey.c

@@ -636,7 +636,11 @@ static const IbexDeviceDef ot_eg_soc_devices[] = {
             OT_EG_SOC_GPIO_SYSBUS_IRQ(0, PLIC, 127),
             OT_EG_SOC_GPIO_SYSBUS_IRQ(1, PLIC, 128),
             OT_EG_SOC_GPIO_SYSBUS_IRQ(2, PLIC, 129),
-            OT_EG_SOC_GPIO_SYSBUS_IRQ(3, PLIC, 130)
+            OT_EG_SOC_GPIO_SYSBUS_IRQ(3, PLIC, 130),
+            OT_EG_SOC_GPIO_ESCALATE(0, IBEX_WRAPPER, 0),
+            OT_EG_SOC_GPIO_ESCALATE(1, LC_CTRL, 0),
+            OT_EG_SOC_GPIO_ESCALATE(1, LC_CTRL, 1),
+            OT_EG_SOC_GPIO_ESCALATE(3, PWRMGR, 0)
         ),
         .link = IBEXDEVICELINKDEFS(
             OT_EG_SOC_DEVLINK("edn", EDN0)