arm: mach-k3: Add secure device build support

K3 HS devices require signed binaries for boot, use the SECDEV tools
to sign the boot artifacts during build.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Andreas Dannenberg <dannenberg@ti.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index dab419e..0e8e3d4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -734,6 +734,7 @@
 F:	arch/arm/mach-omap2/sec-common.c
 F:	arch/arm/mach-omap2/config_secure.mk
 F:	arch/arm/mach-k3/security.c
+F:	arch/arm/mach-k3/config_secure.mk
 F:	configs/am335x_hs_evm_defconfig
 F:	configs/am335x_hs_evm_uart_defconfig
 F:	configs/am43xx_hs_evm_defconfig