ARM: ux500: Remove Snowball DTS entry for TPS61052 chip

TPS61052 is a; boost converter, LED driver, LED flash driver and
simple GPIO pin chip. It has no use here however, as it is not
found on the Snowball development board.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>