mips: octeon: Add minimal Octeon 3 EBB7304 EVK support

This patch adds very basic minimal support for the Marvell Octeon 3
CN73xx based EBB7304 EVK. Please note that the basic Octeon port does
not support DDR3/4 initialization yet. To still use U-Boot on with this
port, the L2 cache (4MiB) is used as RAM. This way, U-Boot can boot
to the prompt on this board.

Supported devices:
- UART
- reset
- CFI parallel NOR flash

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/arch/mips/mach-octeon/Kconfig b/arch/mips/mach-octeon/Kconfig
index 3c8ca8d..e8596ed 100644
--- a/arch/mips/mach-octeon/Kconfig
+++ b/arch/mips/mach-octeon/Kconfig
@@ -31,6 +31,18 @@
 
 endchoice
 
+choice
+	prompt "Octeon 3 board select"
+	default TARGET_OCTEON_EBB7304
+
+config TARGET_OCTEON_EBB7304
+	bool "Marvell Octeon EBB7304"
+	select OCTEON_CN73XX
+	help
+	 Choose this for the Octeon EBB7304 board
+
+endchoice
+
 config SYS_DCACHE_SIZE
 	default 32768
 
@@ -43,4 +55,6 @@
 config SYS_ICACHE_LINE_SIZE
 	default 128
 
+source "board/Marvell/octeon_ebb7304/Kconfig"
+
 endmenu