ARM: dts: ux500: Remove unused ste-href-ab8505.dtsi

ARM: dts: ux500: Remove unused ste-href-ab8505.dtsi

The pin configuration for HREF boards with AB8505 was added in
commit 77ad9dfc2c7e ("ARM: ux500: move last AB8505 set-up to DT").
As the commit message notes, it was unused back then and it has
remained so even today, especially considering AB8505 did not have
proper device tree support until recently.

We are now preparing to add support for some Samsung smartphones
that are using AB8505. However, they use different pin configs
because using ste-href-ab8505.dtsi is known to break UART.
There were not many HREFs with AB8505, so at this point it seems
unlikely that we will ever make use of this include. Remove it.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20191219202052.19039-2-stephan@gerhold.net
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>