clk: samsung: Don't register clkdev lookup for the fixed rate clocks

Commit 4d11c62ca8d7 ("clkdev: report over-sized strings when creating
clkdev entries") revealed that clock lookup is registered for all fixed
clocks. The mentioned commit added a check if the registered name is not
too long. This fails for some clocks registered for Exynos542x SoCs family.
This lookup is a left-over from early common clock framework days, not
really needed nowadays, so remove it to avoid further issues.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Tested-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20240510065901.535124-1-m.szyprowski@samsung.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>