If the Safavids never convert to Shi'a Islam but remain a local dynasty based in Tabriz, just ruling Azerbaijan, or Ismail is defeated as he attempts to take over the Iranian plateau we are left with a power-vacuum in both central -western Iran and Iraq ahead of the Ottoman arrival in the region. The smaller local dynasties who would be ruling the Iraqi cities and tribes are no match for Sultan Selim, and presumably he defeats the locals easier than he did the Safavids at Chaldiran or an equivalent battle. He then overruns Mosul and Baghdad and adds it to the Ottoman empire, though stabilising the region may delay his advance on Mameluke Egypt for a few years. If he succumbs to temptation to play the Alexander and attempt to move onto the Iranian plateau, there will be a clash with the Shaybanids of Uzbekistan, the steppe-origin Uzbek 'empire' based on Bukhara and the Oxus/Samarcand region who in this scenario would not have been defeated by Ismail in 1510.
The Ottoman army with its cannons was more up to date than the cavalry-based steppe Uzbeks, so Selim will probably defeat Mohammed the Shaybanid (k 1510 by Ismail in OTL) and secure the major cities of the plateau, as far as Merv. But the Shaybanids would have been able to retreat to the Oxus or into the steppes and evade pursuit, and the Ottoman army would have been too over-stretched to folow - especially if Selim hankers after Mameluke Egypt as more important and able to secure him religious prestige by taking over Jerusalem and its Caliphal claim. If Selim bothers to go after the Shaybanids across the Iranian plateau he may die (1520 as in OTL?) before he can tackle the Mamelukes; if he leaves them alone after securing the plains of Iraq he may still have time, and extra vassals for his army, to take Syria, Palestine and Egypt. We may still see a clash between the Ottomans and the Shaybanids if the latter recover and threaten Baghdad in the 1520s or 1530s, especially if Mohammed Shaybani is still alive or his son can succeed him and isn't handed over by the Ottomans to Babur and the Mughals (kin to MS's wife).
In that case, a Shaybanid counter-attack on Iraq could distract Sulaiman from his Hungarian war in 1526 or, if Hungary falls on cue, from attacking Vienna in 1529. There is no 'Sunni Ottomans vs Shi'a Iran' religious edge to the Ottoman/ Shaybanid confrontation or threat of the Iranian Shi'a subverting Turcoman tribes in E Anatolia or Iraq to revolt, but the Shaybanids could still have major steppe tribe resources to throw at the Ottomans if they can defeat the Kazakhs to their N. That will drive the Ottomans to retaliate. Or will Sulaiman bribe the Kazakhs to take the Shaybanids in the rear, and succumb to the temptation to extend his E frontier and play the 'new Roman Emperor' role against a weaker foe than the Habsburgs? We might see a 'pivot to the East' and Ottoman attempts to take over the Iranian plain, possibly if Selim had the extra time and determination to persuade his heir to think more in Middle Eastern than European terms for expansion. Or a larger Ottoman mercantile venture from Basra across the Indian Ocean to India to link up with the Mughals for a joint attack on Shaybanid Iran/ Uzbekistan?