sh: mach-highlander and mach-rsk require gpiolib.

Fix up the build for mach-highlander and mach-rsk. These operated on the
assumption that GENERIC_GPIO support with an optional GPIOLIB was
possible. This used to be true, but has not been the case since commit-id
d56cc8bc661ac1ceded8d45ba2d53bb134fee17d ("sh: use gpiolib"), where the
GENERIC_GPIO implementation was rewritten to use GPIOLIB directly.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/boards/Kconfig b/arch/sh/boards/Kconfig
index 802d5c4..c9da370 100644
--- a/arch/sh/boards/Kconfig
+++ b/arch/sh/boards/Kconfig
@@ -240,7 +240,7 @@
 config SH_MAGIC_PANEL_R2
 	bool "Magic Panel R2"
 	depends on CPU_SUBTYPE_SH7720
-	select GENERIC_GPIO
+	select ARCH_REQUIRE_GPIOLIB
 	help
 	  Select Magic Panel R2 if configuring for Magic Panel R2.