Revert "snippets: hw-flow-control: add nrf52"

This reverts commit f65009c.

Signed-off-by: Håkon Amunsden <[email protected]>

Author: hakonfam

snippets/hw-flow-control/boards/nrf52840dk_nrf52840.overlay

@@ -16,9 +16,3 @@ boards:
   nrf54l15dk/nrf54l15/cpuapp:
     append:
       EXTRA_DTC_OVERLAY_FILE: boards/nrf54l15dk_nrf54l15_cpuapp.overlay
-  nrf52840dk/nrf52840:
-    append:
-      EXTRA_DTC_OVERLAY_FILE: boards/nrf52840dk_nrf52840.overlay
-  nrf52dk/nrf52832:
-    append:
-      EXTRA_DTC_OVERLAY_FILE: boards/nrf52dk_nrf52832.overlay