dsp: update size check for get VI param function

In afe_get_cal_sp_th_vi_param functions, data size
should check with size of cal_type_header. The check
is not present which might lead to out of bounds access.

Update condition to ensure data_size is greater than
or equal to size of cal_type_header.

Change-Id: I8fb5cc20102ed4c0ac6708cfa8521e9082d768dc
Signed-off-by: Kunlei Zhang <kunleiz@codeaurora.org>