[nrf fromtree] tests: drivers: spi: spi_error_cases: Cleanup after nRF54LM20 rename

Remove duplicated test configuration after
nrf54l20pdk/nrf54l20/cpuxxx was renamed to
nrf54lm20dk/nrf54lm20a/cpuxxx.

Signed-off-by: Sebastian Głąb <[email protected]>
(cherry picked from commit 467fac1)

Author: nordic-segl

tests/drivers/spi/spi_error_cases/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay

@@ -62,6 +62,7 @@
 	overrun-character = <0x00>;
 	cs-gpios = <&gpio1 3 GPIO_ACTIVE_LOW>;
 	zephyr,pm-device-runtime-auto;
+
 	dut_spi_dt: test-spi-dev@0 {
 		compatible = "vnd,spi-device";
 		reg = <0>;

tests/drivers/spi/spi_error_cases/boards/nrf54lm20dk_nrf54lm20a_cpuapp.overlay

@@ -6,13 +6,13 @@ common:
   harness: ztest
   harness_config:
     fixture: gpio_spi_loopback
+  timeout: 30
 tests:
   drivers.spi.spi_error_cases:
     platform_allow:
       - nrf52840dk/nrf52840
       - nrf54l15dk/nrf54l15/cpuapp
       - nrf54h20dk/nrf54h20/cpuapp
-      - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
       - ophelia4ev/nrf54l15/cpuapp
     integration_platforms: