diag: Change data type of DCI client ID

Make changes to change the type of DCI client id from uint32 to
int as it can now take negative values.

Change-Id: I2e3e76b0188d9504c9a7f82007fbc6f944fc155f
Signed-off-by: Ravi Aravamudhan <aravamud@codeaurora.org>