ACPI / LPSS: Remove redundant initialization of clk

The pointer clk is being initialized to ERR_PTR(-ENODEV) however
this value is never read before it is set to clk_data->clk. Thus
the initialization is redundant and can be mored.

Cleans up clang warning:
Value stored to 'clk' during its initialization is never read

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>