Fix System dump entries route

The system dump entries URI was wrong (same as bmc dump entries) and
hence causes bmcweb to crash with the following error: "handler already
exists for /redfish/v1/Managers/bmc/LogServices/Dump/Entries/"

The below commit has caused this issue:
https://github.com/openbmc/bmcweb/commit/ed3982131dcef2b499da36e674d2d21


b2289ef29
The above change will impact the clients as listing of system dumps will
never work and also this causes bmcweb to crash.

This commit has the fix for the same.
Old Incorrect URI:
/redfish/v1/Managers/bmc/LogServices/Dump/Entries/
is changed to the following RI:
/redfish/v1/Systems/system/LogServices/Dump/Entries/


Tested the same.

Signed-off-by: Asmitha Karunanithi <asmitk01@in.ibm.com>
Change-Id: Idbf23cb2ca52575dd47d296884793a33710e07d5