separation of common and device specific ueventd*.rc config files

[eaut]

I made this pull request to check with you all if you are fine with this approach:

1. it separates device specific ueventd.rc config from common config
2. moves all permission stuff out of init.rc into ueventd.rc
3. adds gyroscope in p1.mk
4. sets more permissions on previously untouched /devs

for now this is p1 only, if you are happy with these changes, then I will make the changes in p1-common accordingly.

@jt1134: I need your feedback on what is device specific and what is common

[jt1134]

I'll look this over this weekend and make the needed changes to p1c