dpctl.device_type.host_device -> dpctl.device_type.host

[oleksandr-pavlyk]

one stray unrefactored use corrected.

Fixes these two test failures:

FAILED dpctl/tests/test_sycl_device_factory.py::test_get_devices_with_string_args[str_args0] - AttributeError: host_device
FAILED dpctl/tests/test_sycl_device_factory.py::test_get_devices_with_device_type_str[host] - AttributeError: host_device

[coveralls]

Coverage increased (+0.4%) to 74.419% when pulling 7b1a61f on fix-test-device-factory into 49ded41 on master.

[oleksandr-pavlyk]

Merging, since only OS compiler workflow runs with host device enabled, but that does not build due to #624 (fixed in #625, but workflow fails pytest due to this issue).

I verified that tests pass locally.