sysfs_devices_system_cpu should be a sysfs_type

Otherwise the following denials occur on mako:

<5>[    2.494246] type=1400 audit(1382544550.200:4): avc:  denied  { associate } for  pid=1 comm="init" name="time_in_state" dev="sysfs" ino=17444 scontext=u:object_r:sy
sfs_devices_system_cpu:s0 tcontext=u:object_r:sysfs:s0 tclass=filesystem
<5>[    2.494735] type=1400 audit(1382544550.200:5): avc:  denied  { associate } for  pid=1 comm="init" name="total_trans" dev="sysfs" ino=17443 scontext=u:object_r:sysf
s_devices_system_cpu:s0 tcontext=u:object_r:sysfs:s0 tclass=filesystem
<5>[    2.495162] type=1400 audit(1382544550.200:6): avc:  denied  { associate } for  pid=1 comm="init" name="stats" dev="sysfs" ino=17442 scontext=u:object_r:sysfs_devi
ces_system_cpu:s0 tcontext=u:object_r:sysfs:s0 tclass=filesystem
<5>[    2.495620] type=1400 audit(1382544550.200:7): avc:  denied  { associate } for  pid=1 comm="init" name="scaling_governor" dev="sysfs" ino=17435 scontext=u:object_r
:sysfs_devices_system_cpu:s0 tcontext=u:object_r:sysfs:s0 tclass=filesystem
<5>[    2.496047] type=1400 audit(1382544550.200:8): avc:  denied  { associate } for  pid=1 comm="init" name="cpuinfo_transition_latency" dev="sysfs" ino=17429 scontext=
u:object_r:sysfs_devices_system_cpu:s0 tcontext=u:object_r:sysfs:s0 tclass=filesystem
<5>[    2.496505] type=1400 audit(1382544550.200:9): avc:  denied  { associate } for  pid=1 comm="init" name="scaling_available_frequencies" dev="sysfs" ino=17439 sconte
xt=u:object_r:sysfs_devices_system_cpu:s0 tcontext=u:object_r:sysfs:s0 tclass=filesystem
<5>[    2.496963] type=1400 audit(1382544550.200:10): avc:  denied  { associate } for  pid=1 comm="init" name="scaling_driver" dev="sysfs" ino=17436 scontext=u:object_r:
sysfs_devices_system_cpu:s0 tcontext=u:object_r:sysfs:s0 tclass=filesystem

Change-Id: I584a1cf61cb871a38be4d3b308cef03e64cfda8e

Move sysfs_devices_system_cpu to the central policy.

Every device has a CPU. This is not device specific.

Allow every domain to read these files/directories.
For unknown reasons, these files are accessed by A LOT
of processes.

Allow ueventd to write to these files. This addresses
the following denials seen on mako:

<5>[    4.935602] type=1400 audit(1383167737.512:4): avc:  denied  { read } for  pid=140 comm="ueventd" name="cpu0" dev="sysfs" ino=3163 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=dir
<5>[    4.935785] type=1400 audit(1383167737.512:5): avc:  denied  { open } for  pid=140 comm="ueventd" name="cpu0" dev="sysfs" ino=3163 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=dir
<5>[    4.935937] type=1400 audit(1383167737.512:6): avc:  denied  { search } for  pid=140 comm="ueventd" name="cpu0" dev="sysfs" ino=3163 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=dir
<5>[    4.936120] type=1400 audit(1383167737.512:7): avc:  denied  { write } for  pid=140 comm="ueventd" name="uevent" dev="sysfs" ino=3164 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=file
<5>[    4.936303] type=1400 audit(1383167737.512:8): avc:  denied  { open } for  pid=140 comm="ueventd" name="uevent" dev="sysfs" ino=3164 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=file

Change-Id: I4766dc571762d8fae06aa8c26828c070b80f5936