arm: bcmbca: add bcm6846 SoC support

BCM6846 is an ARM A7 based PON Broadband SoC. It is part of the BCA
(Broadband Carrier Access origin) chipset family so it's added under
ARCH_BCMBCA platform. This initial support includes a bare-bone
implementation and dts with CPU subsystem, memory and Broadcom uart.

This SoC is supported in the linux-next git repository so the dts and
dtsi files are copied from linux with minor fix-up that needs to be
upstreamed to linux as well.

The u-boot image can be loaded from flash or network to the entry point
address in the memory and boot from there.

Signed-off-by: William Zhang <william.zhang@broadcom.com>
diff --git a/configs/bcm96846_defconfig b/configs/bcm96846_defconfig
new file mode 100644
index 0000000..27cfb45
--- /dev/null
+++ b/configs/bcm96846_defconfig
@@ -0,0 +1,23 @@
+CONFIG_ARM=y
+CONFIG_COUNTER_FREQUENCY=50000000
+CONFIG_ARCH_BCMBCA=y
+CONFIG_SYS_TEXT_BASE=0x01000000
+CONFIG_SYS_MALLOC_LEN=0x2000000
+CONFIG_SYS_MALLOC_F_LEN=0x8000
+CONFIG_BCM6846=y
+CONFIG_TARGET_BCM96846=y
+CONFIG_NR_DRAM_BANKS=1
+CONFIG_DEFAULT_DEVICE_TREE="bcm96846"
+CONFIG_IDENT_STRING=" Broadcom BCM6846"
+CONFIG_SYS_LOAD_ADDR=0x01000000
+CONFIG_ENV_VARS_UBOOT_CONFIG=y
+CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
+CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x2000000
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_DISPLAY_BOARDINFO_LATE=y
+CONFIG_HUSH_PARSER=y
+CONFIG_SYS_MAXARGS=64
+CONFIG_SYS_BOOTM_LEN=0x4000000
+CONFIG_CMD_CACHE=y
+CONFIG_OF_EMBED=y
+CONFIG_CLK=y