configs: Add phycore_am62ax_r5_usbdfu_defconfig

This config includes the phycore_am62ax_r5_defconfig file as well as
the am62x_r5_usbdfu.config fragment. We need another defconfig
because the AM62Ax has not enough internal SRAM to support all boot
sources. The normal phycore_am62ax_r5_defconfig should allow to boot
from MMC and OSPI while this new defconfig allows to boot from USB.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
diff --git a/board/phytec/phycore_am62ax/MAINTAINERS b/board/phytec/phycore_am62ax/MAINTAINERS
index 3e4e2fe..7c8a29b 100644
--- a/board/phytec/phycore_am62ax/MAINTAINERS
+++ b/board/phytec/phycore_am62ax/MAINTAINERS
@@ -10,5 +10,6 @@
 F:	board/phytec/phycore_am62ax/
 F:	configs/phycore_am62ax_a53_defconfig
 F:	configs/phycore_am62ax_r5_defconfig
+F:	configs/phycore_am62ax_r5_usbdfu_defconfig
 F:	include/configs/phycore_am62ax.h
 F:	doc/board/phytec/phycore-am62ax.rst
diff --git a/configs/phycore_am62ax_r5_usbdfu_defconfig b/configs/phycore_am62ax_r5_usbdfu_defconfig
new file mode 100644
index 0000000..34674ce
--- /dev/null
+++ b/configs/phycore_am62ax_r5_usbdfu_defconfig
@@ -0,0 +1,4 @@
+#include <configs/phycore_am62ax_r5_defconfig>
+#include <configs/am62x_r5_usbdfu.config>
+
+CONFIG_USB_GADGET_MANUFACTURER="PHYTEC"