CODEOWNERS: Add codeowner for 96b_wistrio

Add myself as the codeowner for 96Boards Wistrio.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
diff --git a/CODEOWNERS b/CODEOWNERS
index 080e672..f33952f 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -47,6 +47,7 @@
 /boards/arm/96b_nitrogen/                 @idlethread
 /boards/arm/96b_neonkey/                  @Mani-Sadhasivam
 /boards/arm/96b_stm32_sensor_mez/         @Mani-Sadhasivam
+/boards/arm/96b_wistrio/                  @Mani-Sadhasivam
 /boards/arm/arduino_due/                  @ioannisg
 /boards/arm/cc3220sf_launchxl/            @vanti
 /boards/arm/curie_ble/                    @jhedberg