boards: Fix defconfig for tdk_robotkit1

The TDK robokit1 was using the wrong SOC part number by default
which was causing a warning at boot time.

See https://invensense.wpenginepowered.com/wp-content/uploads/2022/09/C21362-TDK-RoboKit1-DK-PLOT.pdf

Signed-off-by: Yuval Peress <peress@google.com>
diff --git a/boards/arm/tdk_robokit1/tdk_robokit1_defconfig b/boards/arm/tdk_robokit1/tdk_robokit1_defconfig
index 60050f372..f5df64d 100644
--- a/boards/arm/tdk_robokit1/tdk_robokit1_defconfig
+++ b/boards/arm/tdk_robokit1/tdk_robokit1_defconfig
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 CONFIG_SOC_SERIES_SAME70=y
-CONFIG_SOC_PART_NUMBER_SAME70Q21=y
+CONFIG_SOC_PART_NUMBER_SAME70Q21B=y
 CONFIG_SOC_ATMEL_SAME70_EXT_MAINCK=y
 CONFIG_SOC_ATMEL_SAME70_PLLA_MULA=24
 CONFIG_SOC_ATMEL_SAME70_PLLA_DIVA=1