platform/surface: Move Surface 3 Button driver to platform/surface

Move the Surface 3 Button driver from platform/x86 to the newly created
platform/surface directory.

Signed-off-by: Maximilian Luz <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Hans de Goede <[e-mail]>

drivers/platform/surface/Kconfig

···
 	  To compile this driver as a module, choose M here: the module will
 	  be called surface3-wmi.
 
+config SURFACE_3_BUTTON
+	tristate "Power/home/volume buttons driver for Microsoft Surface 3 tablet"
+	depends on ACPI && KEYBOARD_GPIO && I2C
+	help
+	  This driver handles the power/home/volume buttons on the Microsoft Surface 3 tablet.
+
 endif # SURFACE_PLATFORMS

drivers/platform/surface/Makefile

···
 #
 
 obj-$(CONFIG_SURFACE3_WMI)		+= surface3-wmi.o
+obj-$(CONFIG_SURFACE_3_BUTTON)		+= surface3_button.o

drivers/platform/x86/Kconfig

···
 	  To compile this driver as a module, choose M here: the module will
 	  be called intel_vbtn.
 
-config SURFACE_3_BUTTON
-	tristate "Power/home/volume buttons driver for Microsoft Surface 3 tablet"
-	depends on ACPI && KEYBOARD_GPIO && I2C
-	help
-	  This driver handles the power/home/volume buttons on the Microsoft Surface 3 tablet.
-
 config SURFACE_3_POWER_OPREGION
 	tristate "Surface 3 battery platform operation region support"
 	depends on ACPI && I2C

drivers/platform/x86/Makefile

···
 obj-$(CONFIG_INTEL_VBTN)		+= intel-vbtn.o
 
 # Microsoft
-obj-$(CONFIG_SURFACE_3_BUTTON)		+= surface3_button.o
 obj-$(CONFIG_SURFACE_3_POWER_OPREGION)	+= surface3_power.o
 obj-$(CONFIG_SURFACE_PRO3_BUTTON)	+= surfacepro3_button.o