doc: board: phytec: Add phyCORE-AM62x

Add documentation for PHYTEC phyCORE-AM62x SoM.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
diff --git a/doc/board/ti/k3.rst b/doc/board/ti/k3.rst
index 7dfe39c..3c33efd 100644
--- a/doc/board/ti/k3.rst
+++ b/doc/board/ti/k3.rst
@@ -33,6 +33,7 @@
    am62ax_sk
    am62x_sk
    ../beagle/am62x_beagleplay
+   ../phytec/phycore-am62x
    ../toradex/verdin-am62
    am64x_evm
    am65x_evm