staging: mt7621-dts: change palmbus address to lower case

Hexadecimal addresses in device tree must be defined using lower case.
Change missing one in 'gbpc1.dts' file.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20211019102915.15409-1-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>