soc: nordic: nrf54h20: Make HSFLL trims optional

If no HSFLL needs trimming, then `trim_hsfll()` should be compiled out.
This makes it easier to reuse the rest of `soc.c` out of tree.

Furthermore, some HSFLL instances can be trimmed before booting Zephyr,
so the FICR client properties in the DT binding should not be required.

Signed-off-by: Grzegorz Swiderski <grzegorz.swiderski@nordicsemi.no>

dts/bindings/clock/nordic,nrf-hsfll.yaml

@@ -57,9 +57,3 @@ properties:
       - 368000000
       - 384000000
       - 400000000
-
-  nordic,ficrs:
-    required: true
-
-  nordic,ficr-names:
-    required: true