Bluetooth: btmtk: adjust the position to init iso data anchor

Bluetooth: btmtk: adjust the position to init iso data anchor

MediaTek iso data anchor init should be moved to where MediaTek
claims iso data interface.
If there is an unexpected BT usb disconnect during setup flow,
it will cause a NULL pointer crash issue when releasing iso
anchor since the anchor wasn't been init yet. Adjust the position
to do iso data anchor init.

[   17.137991] pc : usb_kill_anchored_urbs+0x60/0x168
[   17.137998] lr : usb_kill_anchored_urbs+0x44/0x168
[   17.137999] sp : ffffffc0890cb5f0
[   17.138000] x29: ffffffc0890cb5f0 x28: ffffff80bb6c2e80
[   17.144081] gpio gpiochip0: registered chardev handle for 1 lines
[   17.148421]  x27: 0000000000000000
[   17.148422] x26: ffffffd301ff4298 x25: 0000000000000003 x24: 00000000000000f0
[   17.148424] x23: 0000000000000000 x22: 00000000ffffffff x21: 0000000000000001
[   17.148425] x20: ffffffffffffffd8 x19: ffffff80c0f25560 x18: 0000000000000000
[   17.148427] x17: ffffffd33864e408 x16: ffffffd33808f7c8 x15: 0000000000200000
[   17.232789] x14: e0cd73cf80ffffff x13: 50f2137c0a0338c9 x12: 0000000000000001
[   17.239912] x11: 0000000080150011 x10: 0000000000000002 x9 : 0000000000000001
[   17.247035] x8 : 0000000000000000 x7 : 0000000000008080 x6 : 8080000000000000
[   17.254158] x5 : ffffffd33808ebc0 x4 : fffffffe033dcf20 x3 : 0000000080150011
[   17.261281] x2 : ffffff8087a91400 x1 : 0000000000000000 x0 : ffffff80c0f25588
[   17.268404] Call trace:
[   17.270841]  usb_kill_anchored_urbs+0x60/0x168
[   17.275274]  btusb_mtk_release_iso_intf+0x2c/0xd8 [btusb (HASH:5afe 6)]
[   17.284226]  btusb_mtk_disconnect+0x14/0x28 [btusb (HASH:5afe 6)]
[   17.292652]  btusb_disconnect+0x70/0x140 [btusb (HASH:5afe 6)]
[   17.300818]  usb_unbind_interface+0xc4/0x240
[   17.305079]  device_release_driver_internal+0x18c/0x258
[   17.310296]  device_release_driver+0x1c/0x30
[   17.314557]  bus_remove_device+0x140/0x160
[   17.318643]  device_del+0x1c0/0x330
[   17.322121]  usb_disable_device+0x80/0x180
[   17.326207]  usb_disconnect+0xec/0x300
[   17.329948]  hub_quiesce+0x80/0xd0
[   17.333339]  hub_disconnect+0x44/0x190
[   17.337078]  usb_unbind_interface+0xc4/0x240
[   17.341337]  device_release_driver_internal+0x18c/0x258
[   17.346551]  device_release_driver+0x1c/0x30
[   17.350810]  usb_driver_release_interface+0x70/0x88
[   17.355677]  proc_ioctl+0x13c/0x228
[   17.359157]  proc_ioctl_default+0x50/0x80
[   17.363155]  usbdev_ioctl+0x830/0xd08
[   17.366808]  __arm64_sys_ioctl+0x94/0xd0
[   17.370723]  invoke_syscall+0x6c/0xf8
[   17.374377]  el0_svc_common+0x84/0xe0
[   17.378030]  do_el0_svc+0x20/0x30
[   17.381334]  el0_svc+0x34/0x60
[   17.384382]  el0t_64_sync_handler+0x88/0xf0
[   17.388554]  el0t_64_sync+0x180/0x188
[   17.392208] Code: f9400677 f100a2f4 54fffea0 d503201f (b8350288)
[   17.398289] ---[ end trace 0000000000000000 ]---

Fixes: ceac1cb0259d ("Bluetooth: btusb: mediatek: add ISO data transmission functions")
Signed-off-by: Chris Lu <chris.lu@mediatek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>