Fixed incorrect references in Led/Readme.md.

Existing references contained the wrong path to Led/Group.Interface.yaml
and Physical.Interface.yaml.
Also reference in chapter "Dbus interfaces for physical LEDs"
referred to Group.Interface.yaml instead of Physical.Interface.yaml.

This commit fixes file paths and enters two different references
(for Group and for Physical).

Signed-off-by: Vladimir Kuznetsov <v.kuznetsov@yadro.com>
Change-Id: Ib34a470f366db4657fd6d6e49b109a79319f79c3
diff --git a/yaml/xyz/openbmc_project/Led/README.md b/yaml/xyz/openbmc_project/Led/README.md
index 91eed5d..b6d259a 100644
--- a/yaml/xyz/openbmc_project/Led/README.md
+++ b/yaml/xyz/openbmc_project/Led/README.md
@@ -63,9 +63,9 @@
 
 ## Dbus interfaces for LED groups
 
-Refer to the [specification][specification].
+Refer to the [specification][group_specification].
 
-[specification]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/Led/Group.interface.yaml
+[group_specification]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/yaml/xyz/openbmc_project/Led/Group.interface.yaml
 
 There is only one property called **asserted** defined on groups and when set to
 boolean **true**, the actions listed for the LEDs in that group will get into
@@ -110,9 +110,9 @@
 
 ## Dbus interfaces for physical LEDs
 
-Refer to the [specification][specification].
+Refer to the [specification][phys_specification].
 
-[specification]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/Led/Physical.interface.yaml
+[phys_specification]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/yaml/xyz/openbmc_project/Led/Physical.interface.yaml
 
 ## Dbus information