udev-extraconf: Drop changes merged upstream

The patch to unmount SD card after improper ejection
from card reader by handling the CHANGE event in udev
rules has been merged upstream as of commit id
0cd5af027234735fe83d0681dbdddb197c02f262. Therefore
we don't need to maintain these changes now.

Signed-off-by: Yasir-Khan <yasir_khan@mentor.com>
Merge pull request #283 from Yasir-Khan/udev

udev-extraconf: Drop changes merged upstream