docs: extcon: convert it to ReST and move to ACPI dir

The intel-int3496.txt file is a documentation for an ACPI driver.

There's no reason to keep it on a separate directory.

So, instead of keeping it on some random location, move it
to a sub-directory inside the ACPI documentation dir,
renaming it to .rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Documentation/extcon/intel-int3496.txt → Documentation/firmware-guide/acpi/extcon-intel-int3496.rst

+=====================================================
 Intel INT3496 ACPI device extcon driver documentation
------------------------------------------------------
+=====================================================
 
 The Intel INT3496 ACPI device extcon driver is a driver for ACPI
 devices with an acpi-id of INT3496, such as found for example on
@@ -13,15 +14,20 @@ between an USB host and an USB peripheral controller.
 The ACPI devices exposes this functionality by returning an array with up
 to 3 gpio descriptors from its ACPI _CRS (Current Resource Settings) call:
 
-Index 0: The input gpio for the id-pin, this is always present and valid
-Index 1: The output gpio for enabling Vbus output from the device to the otg
+=======  =====================================================================
+Index 0  The input gpio for the id-pin, this is always present and valid
+Index 1  The output gpio for enabling Vbus output from the device to the otg
          port, write 1 to enable the Vbus output (this gpio descriptor may
          be absent or invalid)
-Index 2: The output gpio for muxing of the data pins between the USB host and
+Index 2  The output gpio for muxing of the data pins between the USB host and
          the USB peripheral controller, write 1 to mux to the peripheral
          controller
+=======  =====================================================================
 
 There is a mapping between indices and GPIO connection IDs as follows
+
+	======= =======
 	id	index 0
 	vbus	index 1
 	mux	index 2
+	======= =======

Documentation/firmware-guide/acpi/index.rst

@@ -24,3 +24,4 @@ ACPI Support
    acpi-lid
    lpit
    video_extension
+   extcon-intel-int3496

MAINTAINERS

@@ -321,7 +321,7 @@ F:	drivers/pnp/pnpacpi/
 F:	include/linux/acpi.h
 F:	include/linux/fwnode.h
 F:	include/acpi/
-F:	Documentation/acpi/
+F:	Documentation/firmware-guide/acpi/
 F:	Documentation/ABI/testing/sysfs-bus-acpi
 F:	Documentation/ABI/testing/configfs-acpi
 F:	drivers/pci/*acpi*
@@ -4862,7 +4862,7 @@ S:	Maintained
 F:	Documentation/
 F:	scripts/kernel-doc
 X:	Documentation/ABI/
-X:	Documentation/acpi/
+X:	Documentation/firmware-guide/acpi/
 X:	Documentation/devicetree/
 X:	Documentation/i2c/
 X:	Documentation/media/
@@ -6032,7 +6032,7 @@ S:	Maintained
 F:	drivers/extcon/
 F:	include/linux/extcon/
 F:	include/linux/extcon.h
-F:	Documentation/extcon/
+F:	Documentation/firmware-guide/acpi/extcon-intel-int3496.rst
 F:	Documentation/devicetree/bindings/extcon/
 
 EXYNOS DP DRIVER