tests: drivers: spi: siwx91x: Enable spi_loopback test for PSRAM board

Update testcase.yaml to enable the spi_loopback test for the
siwx917_rb4342a board.

Signed-off-by: Sai Santhosh Malae <[email protected]>

Author: smalae

tests/drivers/spi/spi_loopback/testcase.yaml

@@ -360,6 +360,12 @@ tests:
     filter: CONFIG_SOC_FAMILY_SILABS_SIWX91X
     platform_allow:
       - siwx917_rb4338a
+      - siwx917_rb4342a
+    extra_configs:
+      - CONFIG_SPI_SILABS_SIWX91X_GSPI_DMA=y
+      - CONFIG_SPI_IDEAL_TRANSFER_DURATION_SCALING=30
+    extra_args:
+      - DTC_OVERLAY_FILE="boards/siwx917_rb4338a.overlay"
   drivers.spi.cc23x0.loopback.dma.no_async:
     filter: CONFIG_SOC_FAMILY_TI_SIMPLELINK
     platform_allow: