ACPICA: Unix: Cleanup to use ACPI_TO_INTEGER() to calc page offset.

ACPICA commit 9e2d8180f4d5e61949b17513bae8aff6412f62dd

The offset calculation needn't convert a pointer to a special integer type.
So this patch uses ACPI_TO_INTEGER() instead.

This patch only affects acpidump tool.

Link: https://github.com/acpica/acpica/commit/9e2d8180


Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>