[PATCH v2] docs: ABI: correct QEMU fw_cfg spec path

["Jason A. Donenfeld" <Jason@zx2c4.com>]

A few weeks ago, QEMU switched docs/specs/fw_cfg.txt to be
docs/specs/fw_cfg.rst, so update the reference in the kernel docs to
reflect this. Also add a link to the online documentation to make it
easier to find.

Cc: Simon Sapin <simon.sapin@exyr.org>
Cc: Gabriel Somlo <somlo@cmu.edu>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg b/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg
index ee0d6dbc810e..54d1bfd0db12 100644
--- a/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg
+++ b/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg
@@ -12,8 +12,9 @@ Description:
 		configuration data to the guest userspace.
 
 		The authoritative guest-side hardware interface documentation
-		to the fw_cfg device can be found in "docs/specs/fw_cfg.txt"
-		in the QEMU source tree.
+		to the fw_cfg device can be found in "docs/specs/fw_cfg.rst"
+		in the QEMU source tree, or online at:
+		https://qemu-project.gitlab.io/qemu/specs/fw_cfg.html
 
 		**SysFS fw_cfg Interface**
 
-- 
2.35.1