xen/riscv: finalize boot allocator and transition to boot state

Add a call to end_boot_allocator() in start_xen() to finalize the
boot memory allocator, moving free pages to the domain sub-allocator.

After initializing the memory subsystem, update `system_state` from
`SYS_STATE_early_boot` to `SYS_STATE_boot`, signifying the end of the
early boot phase.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/riscv/setup.c

@@ -65,6 +65,14 @@ void __init noreturn start_xen(unsigned long bootcpu_id,
 
     vm_init();
 
+    end_boot_allocator();
+
+    /*
+     * The memory subsystem has been initialized, we can now switch from
+     * early_boot -> boot.
+     */
+    system_state = SYS_STATE_boot;
+
     printk("All set up\n");
 
     machine_halt();