ACPI: x86: Call acpi_boot_table_init() after acpi_table_upgrade()

Commit 1a1c130a ("ACPI: tables: x86: Reserve memory occupied by
ACPI tables") attempted to address an issue with reserving the memory
occupied by ACPI tables, but it broke the initrd-based table override
mechanism relied on by multiple users.

To restore the initrd-based ACPI table override functionality, move
the acpi_boot_table_init() invocation in setup_arch() on x86 after
the acpi_table_upgrade() one.

Fixes: 1a1c130a

 ("ACPI: tables: x86: Reserve memory occupied by ACPI tables")
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>