msm: ipa3: Add proper check for FNR stats query

In some targets, FnR tethering stats query support
is not present. Add changes to check for support
present or not before query.

Change-Id: I415e019ff0cb01cf09c8ba6cd9fef44ae815c11b
Signed-off-by: Praveen Kurapati <pkurapat@codeaurora.org>