Add test against SDIO+FATFS read

[danielinux]

• [x] Test using open()/read()
• [ ] Test using fopen()/fread()

[brabo]

Test for open/read added in https://github.com/insane-adding-machines/frosted-userland/commit/a8bbe1ed804eaaa8b3263d0cd43fd71938256753