Say what? KSA has been bombing Daesh in Syria for over 1 year now along with many other Arab nations. Before the conflict in Yemen began last year KSA along with the US were using drones against AQAP. The reason why AQAP are only sporadically attacked nowadays is because it would be totally unwise to open a third front and because the Houthi's are a bigger threat now.
Just like Al-Assad is never attacking Daesh directly but focusing on FSA and Ahrar al-Sham.
Saudi prince and UAE's first female pilot lead blitz on ISIS in Iraq and Syria | Daily Mail Online
Just because Iranian state media does not report such news (only mostly propaganda or outright lies) it does mean that it's not truth. You can find plenty of videos of Saudi Arabian pilots bombing numerous Daesh targets in Syria.
Anyway this is off-topic.
Lastly if you are genuinely interested in knowing about Yemen read my previous post on the last page (post 56).