ocfs2: update mount option documentation
ocfs2: update mount option documentation

We forgot to document the atime_quantum mount option in ocfs2.txt. This adds
a proper description of how it works.

Signed-off-by: Tiger Yang <a9266d1c80010dce13c350637464d65d95b31d98@oracle.com>
Signed-off-by: Mark Fasheh <3dfef03b24d35cb667816693d0487c922cd46885@oracle.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs