generic: ar8216: clear driver specific data pointer in phy_device

generic: ar8216: clear driver specific data pointer in phy_device

This is needed to avoid a NULL pointer dereference:

  [   19.525270] Unable to handle kernel paging request for data at address 0x00000018
  [   19.532750] Faulting instruction address: 0xc016e104
  [   19.537714] Oops: Kernel access of bad area, sig: 11 [#1]
  [   19.543102] P1010 RDB
  [   19.545365] Modules linked in: booke_wdt nf_nat_irc nf_nat_ftp nf_conntrack_irc nf_conntrack_ftp ipt_MASQUERADE iptable_nat xt_nat d
  [   19.590725] NIP: c016e104 LR: c0171490 CTR: 00000000
  [   19.595681] REGS: c4bc3c10 TRAP: 0300   Tainted: G        W  O (3.7.6)
  [   19.602284] MSR: 00029000 <CE,EE,ME>  CR: 82002022  XER: 20000000
  [   19.608381] DEAR: 00000018, ESR: 00000000
  [   19.612382] TASK = c4cd9c80[2070] 'ifconfig' THREAD: c4bc2000
  GPR00: 00000001 c4bc3cc0 c4cd9c80 00000000 c7811000 00000000 00000000 0000e8ec
  GPR08: 0000e8eb 00000000 00029000 00000001 00000000 100801f8 1005c51c 1005c514
  GPR16: 1005c468 1005c54c 1005c258 1005c530 10060000 00000000 c7811000 ffff8914
  GPR24: c7815030 c793e400 10063adb 00000000 c7811000 c045594c c78ca600 c7815000
  [   19.646352] NIP [c016e104] register_switch+0x98/0x2d0
  [   19.651397] LR [c0171490] ar8216_config_init+0x2d8/0x3f4
  [   19.656697] Call Trace:
  [   19.659138] [c4bc3cc0] [c0170490] ar8216_mii_read+0x64/0xc4 (unreliable)
  [   19.665835] [c4bc3d00] [c0171490] ar8216_config_init+0x2d8/0x3f4
  [   19.671835] [c4bc3d20] [c016cf8c] phy_init_hw+0x50/0x6c
  [   19.677053] [c4bc3d30] [c016d078] phy_attach_direct+0xd0/0xf8
  [   19.682793] [c4bc3d50] [c016d154] phy_connect_direct+0x24/0x68
  [   19.688621] [c4bc3d70] [c0183b70] of_phy_connect+0x48/0x6c
  [   19.694102] [c4bc3d90] [c0175aac] gfar_enet_open+0x254/0x3d8
  [   19.699755] [c4bc3db0] [c019acc4] __dev_open+0xc0/0x120
  [   19.704975] [c4bc3dd0] [c019af98] __dev_change_flags+0xd4/0x15c
  [   19.710888] [c4bc3df0] [c019b0d4] dev_change_flags+0x1c/0x60
  [   19.716544] [c4bc3e10] [c01ebb94] devinet_ioctl+0x290/0x690
  [   19.722111] [c4bc3e70] [c01ec8d4] inet_ioctl+0x88/0xbc
  [   19.727245] [c4bc3e80] [c0186b98] sock_ioctl+0x258/0x294
  [   19.732551] [c4bc3ea0] [c009c00c] do_vfs_ioctl+0x6a4/0x728
  [   19.738031] [c4bc3f10] [c009c0d4] sys_ioctl+0x44/0x70
  [   19.743077] [c4bc3f40] [c000c74c] ret_from_syscall+0x0/0x3c
  [   19.748646] --- Exception: c01 at 0x48091b34
  [   19.748646]     LR = 0x480e4b64
  [   19.756033] Instruction dump:
  [   19.758991] 2f830000 907f0050 3860fff4 419e021c 837f0000 38000000 901f0038 901f0040
  [   19.766744] 901f003c 7f600034 5400d97e 0f000000 <801b0018> 2f800000 40be0010 801b001c

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
SVN-Revision: 35497