ACPICA: Remove obsolete ACPI_INTEGER (acpi_integer) type

This type was introduced as the code was migrated from ACPI 1.0
(with 32-bit AML integers) to ACPI 2.0 (with 64-bit integers). It
is now obsolete and this change removes it from the ACPICA code
base, replaced by u64.  The original typedef has been retained
for now for compatibility with existing device driver code.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>