Turns out that the MRAA version I had was an older version which probably did not set the default #bits to 10.
It did not even have the setBit, getBit methods. This is the MRAA that came with the latest yocto image and I had not checked the MRAA version until now.
After I updated the MRAA to latest version, analog read is working fine.
Thanks Deigo for pointing me to the correct documentation. It was right there but I was somehow missing it in haste.
Regards,
Nischal