ACPI: Documentation: Remove driver-api/acpi/acpi-drivers.rst
Remove the file added by commit b8c8a8ea18ad ("ACPI: Documentation:
driver-api: Disapprove of using ACPI drivers") because it is not
necessary any more after eliminating struct acpi_driver from the code.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>