default or selected kernelversion does not have config value CONFIG_IP_DCCP_CCID2.
Result is shown for kernelversion 5.3.7

CCID2 (TCP-Like) (EXPERIMENTAL)

modulename: dccp_ccid2.ko

configname: CONFIG_IP_DCCP_CCID2

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>The DCCP Protocol (EXPERIMENTAL)
└─>DCCP CCIDs Configuration (EXPERIMENTAL)
└─>CCID2 (TCP-Like) (EXPERIMENTAL)
In linux kernel since version 2.6.17 (release Date: 2006-06-17)  
CCID 2, TCP-like Congestion Control, denotes Additive Increase,
Multiplicative Decrease (AIMD) congestion control with behavior
modelled directly on TCP, including congestion window, slow start,
timeouts, and so forth [RFC 2581]. CCID 2 achieves maximum
bandwidth over the long term, consistent with the use of end-to-end
congestion control, but halves its congestion window in response to
each congestion event. This leads to the abrupt rate changes
typical of TCP. Applications should use CCID 2 if they prefer
maximum bandwidth utilization to steadiness of rate. This is often
the case for applications that are not playing their data directly
to the user. For example, a hypothetical application that
transferred files over DCCP, using application-level retransmissions
for lost packets, would prefer CCID 2 to CCID 3. On-line games may
also prefer CCID 2. See RFC 4341 for further details.

CCID2 is the default CCID used by DCCP.

source code:

depends
CONFIG_EXPERIMENTAL
CONFIG_IP_DCCP
CONFIG_NET

is depended by
CONFIG_IP_DCCP