"How far away is the grocery store?"
"Eh, ten minutes' walk."
"A ten minute walk."
- Both answers are correct and used often. The first answer implies more of a guesstimation of time, whereas the second implies exact knowledge of time involved.
However, the word 'talk' has evolved to be used primarily as a verb, not a noun. Its usage as a noun has largely faded from the English language. For instances where modern native English speakers would end up using 'talk' in the descriptive sense (as a noun), they will almost always substitute it for another, more descriptive word, or change the structure of the sentence so that 'talk' becomes a verb. If one does not do so, they will sound archaic at best (even if it is technically correct grammatically).
"There was a talk on politics" -> "There was a seminar on politics".
"Come inside for ten minutes' talk." -> "Let's talk for ten minutes."
Edge case: "He gave a talk on politics" - might be acceptable.