ARM: dts: Add devicetree for Samsung GT-S7710

The Samsung GT-S7710 also known as XCover 2 or Skomer is a
Ux500-based mobile phone. In the source code release from
Samsung's open source site it is referred to as "Skomer".
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20200307193627.4092-1-linus.walleij@linaro.org
[Typographic fixups when applying]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/boot/dts/Makefile

@@ -1202,7 +1202,8 @@ dtb-$(CONFIG_ARCH_U8500) += \
 	ste-hrefv60plus-stuib.dtb \
 	ste-hrefv60plus-tvk.dtb \
 	ste-href520-tvk.dtb \
-	ste-ux500-samsung-golden.dtb
+	ste-ux500-samsung-golden.dtb \
+	ste-ux500-samsung-skomer.dtb
 dtb-$(CONFIG_ARCH_UNIPHIER) += \
 	uniphier-ld4-ref.dtb \
 	uniphier-ld6b-ref.dtb \