brcm63xx: move RTA770(B)W to dts

target/linux/brcm63xx/base-files/lib/brcm63xx.sh

target/linux/brcm63xx/dts/rta770bw.dts

target/linux/brcm63xx/dts/rta770w.dts

target/linux/brcm63xx/image/Makefile

target/linux/brcm63xx/patches-3.14/533-board_rta770bw.patch

target/linux/brcm63xx/patches-3.14/534-board_hw556.patch

target/linux/brcm63xx/patches-3.14/535-board_rta770w.patch

target/linux/brcm63xx/patches-3.14/536-board_fast2704.patch

target/linux/brcm63xx/patches-3.14/537-board_fast2504n.patch

...tches-3.14/550-MIPS-BCM63XX-remove-leds-and-buttons.patch

...linux/brcm63xx/patches-3.14/553-boards_probe_switch.patch

target/linux/brcm63xx/patches-3.14/555-board_96318ref.patch

...linux/brcm63xx/patches-3.14/556-board_96318ref_p300.patch

.../linux/brcm63xx/patches-3.14/557-board_bcm963269bhr.patch

target/linux/brcm63xx/patches-3.14/558-board_AR1004G.patch

target/linux/brcm63xx/patches-3.14/559-board_vw6339gu.patch

...linux/brcm63xx/patches-3.14/560-board_963268gu_p300.patch

target/linux/brcm63xx/patches-3.14/561-board_WAP-5813n.patch

target/linux/brcm63xx/patches-3.14/562-board_VR-3025u.patch

target/linux/brcm63xx/patches-3.14/563-board_VR-3025un.patch