MIPS: BMIPS: Add support UART, I2C, SATA device

Add UART, I2C, SATA device tree nodes on Broadcom BCM7xxx MIPS-based
platforms.

Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Dragan Stancevic <dragan.stancevic@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/13016/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>