A Real Estate "Professional" still is not considered as self employment income. You would need to be a Real Estate "Dealer" (sale of real estate), or provide significant services for the rental property for it to be self employment income (which the profit would be subject to self employment tax).
In other words, your real estate rental is not eligible for a SEP:
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/publications/p560/ch01.html#en_US_2014_publink10008810">https://www.irs.gov/publ...>
<a rel="nofollow" target="_blank" href="
https://www.law.cornell.edu/uscode/text/26/401#c_2">https://www.law.cornell.edu/uscode/text/26/401#c...>
