armv7R: K3: am654: Add support for generating build targets

Update Makefiles to generate:
- tiboot3.bin: Image format that can be processed by ROM.

Below is the tiboot3.bin image format that is required by ROM:

		 _______________________
		|	 X509		|
		|     Certificate	|
		| ____________________	|
		| |		      |	|
		| | u-boot-spl.bin    |	|
		| |		      |	|
		| |___________________|	|
		|_______________________|

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
diff --git a/arch/arm/mach-k3/Kconfig b/arch/arm/mach-k3/Kconfig
index 2df6197..9f5e8e5 100644
--- a/arch/arm/mach-k3/Kconfig
+++ b/arch/arm/mach-k3/Kconfig
@@ -47,5 +47,16 @@
 	  Address at which ROM stores the value which determines if SPL
 	  is booted up by primary boot media or secondary boot media.
 
+config SYS_K3_KEY
+	string "Key used to generate x509 certificate"
+	help
+	  This option enables to provide a custom key that can be used for
+	  generating x509 certificate for spl binary. If not needed leave
+	  it blank so that a random key is generated and used.
+
+config SYS_K3_BOOT_CORE_ID
+	int
+	default 16
+
 source "board/ti/am65x/Kconfig"
 endif