Change DHCP rate limit(queue4,group3) in SONiC copp configuration to 300 PPS
    for mgmt TORs while keeping the rate limit at 100 PPS for other topologies.

    Why I did it:
    Some mgmt TORs based on Marvell ASIC do not support 100 PPS CIR, so that led
    to these devices silently dropping DHCP packets.

    Microsoft ADO: **25820076**

    How to verify it:
    Send DHCP broadcast packets to an M0 DUT and verify that they are trapped to
    CPU at 300 PPS. On non-mgmt devices, the packets should be trapped at CIR of
    100 PPS. Also ran sonic-mgmt dhcp_relay test and confirmed that it passes.

Signed-off-by: Prabhat Aravind <paravind@microsoft.com>

 * Modify condition check for Mgmt devices

Signed-off-by: Prabhat Aravind <paravind@microsoft.com>