doc: Remove nrf54lm20pdk occurences

Signed-off-by: Karol Lasończyk <[email protected]>

Author: kl-cruz

doc/nrf/includes/sample_board_rows.txt

@@ -258,10 +258,6 @@
 
 | nRF54LV10 DK |   | nrf54lv10dk | ``nrf54lv10dk/nrf54lv10a/cpuapp`` |
 
-.. nrf54lm20pdk_nrf54lm20a_cpuapp
-
-| nRF54LM20 PDK |   | nrf54lm20pdk | ``nrf54lm20pdk/nrf54lm20a/cpuapp`` |
-
 .. nrf54lm20dk_nrf54lm20a_cpuapp
 
 | nRF54LM20 DK |   | nrf54lm20dk | ``nrf54lm20dk/nrf54lm20a/cpuapp`` |