ARM: dts: bcm2835-rpi-b: Fix GPIO line names

Recently this has been fixed in the vendor tree, so upstream this.

Fixes: 731b26a6 ("ARM: bcm2835: Add names for the Raspberry Pi GPIO lines")
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>