mhi: cntrl: qcom: remove multiple calls to sysfs_create_group()

There is a warning due to multiple calls to sysfs_create_group()
function. Remove the second call as it is not required and will
ensure unnecessary warning or error messages are not seen.

Change-Id: Ibf9dec627be328fc885c055eb28f2743b52b30f7
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>