It had looked like a troubled deal for quite some time, but now it is official. Qualcomm has canceled its $44bn takeover of NXP, the Dutch chip specialist that Qualcomm had eyed up for its IoT expertise. NXP is getting a $2bn exit fee, and Qualcomm is now kicking off a $30bn share buyback program. This was the largest IoT acquisition, eclipsing SoftBank’s $32bn purchase of ARM, but now it’s been canned. Rising tensions between the US and China will have played a part in China’s reluctance to hand over approval for the deal. The US and EU very quickly announced their consent, but China always seemed wary. There have been other IoT deals blocked on these concerns, although usually…