ASoC: tegra-alt: Fix crash when 'rt565x-playback' link is not defined

ASoC: tegra-alt: Fix crash when 'rt565x-playback' link is not defined

If the 'rt565x-playback' link is not defined in device-tree for the
Tegra186 rt565x machine driver then the following crash is seen ...

 Unable to handle kernel NULL pointer dereference at virtual address 00000068
 pgd = ffffffc0014f1000
 [00000068] *pgd=000000026cdd6003, *pud=000000026cdd6003, *pmd=000000026cdd7003, *pte=00e8000003881707
 Internal error: Oops: 96000005 [#1] PREEMPT SMP
 Modules linked in:
 CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.4.38-tegra #116
 Hardware name: quill (DT)
 task: ffffffc1ece78000 ti: ffffffc1ece80000 task.ti: ffffffc1ece80000
 PC is at rt5659_set_jack_detect+0x8/0x38
 LR is at tegra_t186ref_driver_probe+0x4a8/0x4f8
 pc : [<ffffffc0009a1e94>] lr : [<ffffffc0009bad8c>] pstate: 60000045
 sp : ffffffc1ece83b80
 x29: ffffffc1ece83b80 x28: ffffffc1e1beb118
 x27: 000000000000000d x26: ffffffc0013dabd8
 x25: ffffffc1e1bec218 x24: ffffffc1e1beb118
 x23: 0000000000000000 x22: ffffffc1e1beb120
 x21: 0000000000000000 x20: ffffffc1ebb4ac10
 x19: ffffffc0013da940 x18: 0000000000000000
 x17: ffffffc000b85a60 x16: ffffffc000b85a60
 x15: ffffffc000b85a60 x14: 6b6e696c20636564
 x13: 6f63203a646e756f x12: 7320783536357472
 x11: 2d656c69626f6d2d x10: 666572363831742d
 x9 : 00000000000002ca x8 : 0000000000000001
 x7 : ffffffc1ece80000 x6 : 0000000000000000
 x5 : 0000000000000000 x4 : 0000000000000000
 x3 : 0000000000000000 x2 : 0000000000000000
 x1 : ffffffc0014d6150 x0 : 0000000000000000

 Process swapper/0 (pid: 1, stack limit = 0xffffffc1ece80020)
 Call trace:
 [<ffffffc0009a1e94>] rt5659_set_jack_detect+0x8/0x38
 [<ffffffc0009bad8c>] tegra_t186ref_driver_probe+0x4a8/0x4f8
 [<ffffffc000597518>] platform_drv_probe+0x50/0xbc
 [<ffffffc000594fa8>] driver_probe_device+0xc8/0x408
 [<ffffffc000595384>] __driver_attach+0x9c/0xa0
 [<ffffffc000593004>] bus_for_each_dev+0x58/0x98
 [<ffffffc000594a30>] driver_attach+0x20/0x28
 [<ffffffc0005945a0>] bus_add_driver+0x1f0/0x294
 [<ffffffc000596204>] driver_register+0x68/0x108
 [<ffffffc00059745c>] __platform_driver_register+0x54/0x5c
 [<ffffffc00117b880>] tegra_t186ref_driver_init+0x1c/0x24
 [<ffffffc000081ab4>] do_one_initcall+0xc8/0x1c0
 [<ffffffc00112fb70>] kernel_init_freeable+0x1dc/0x280
 [<ffffffc000b74b8c>] kernel_init+0x10/0xe0
 [<ffffffc000084f90>] ret_from_fork+0x10/0x40
 ---[ end trace 0cb34349b16e5280 ]---

This crash is caused because when the 'rt565x-playback' link is not
defined we will still call rt5659_set_jack_detect() but pass a NULL
pointer for the codec handle. Fix this by ensuring we only call
rt5659_set_jack_detect() when the 'rt565x-playback' link is present.

Bug 2045523

Change-Id: I4c6a57ae5df6e1c976c81ff0557534eecea581bc
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1636472
GVS: Gerrit_Virtual_Submit
Reviewed-by: Mohan Kumar D <mkumard@nvidia.com>
Reviewed-by: Sameer Pujar <spujar@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>