fix(epicardium): Increase pmic stacksize

With the PMIC task calling graphics code, it now needs a bit more stack
space.  Increase the allocation to ensure we won't get a stack overflow
here.

epicardium/main.c

@@ -92,7 +92,7 @@ int main(void)
 	if (xTaskCreate(
 		    vPmicTask,
 		    (const char *)"PMIC",
-		    configMINIMAL_STACK_SIZE,
+		    configMINIMAL_STACK_SIZE * 3,
 		    NULL,
 		    tskIDLE_PRIORITY + 4,
 		    NULL) != pdPASS) {