memory: mtk-smi: Degrade SMI init to module_init

memory: mtk-smi: Degrade SMI init to module_init

The initialization of MediaTek power manager(SCPSYS) is
builtin_platform_driver, and SMI must depend on power-domain.
Thus, currently subsys_initcall for SMI is unnecessary, SMI will be
always probe defered by power-domain. Degrade it to module_init.

In addition, there are two small changes about the probe sequence:
1) Delete this two lines.
    	if (!dev->pm_domain)
		return -EPROBE_DEFER;
   This is not helpful. the platform driver framework guarantee this.
   The "dev_pm_domain_attach" in the "platform_drv_probe" will return
   EPROBE_DEFER if its powerdomain is not ready.

2) Add the probe-defer for the smi-larb device should waiting for
   smi-common.
   In mt2712, there are 2 smi-commons, 10 smi-larbs. All will be
   probe-defered by the power-domain, there is seldom case that
   smi-larb probe done before smi-common. then it will hang like
   this:

   Unable to handle kernel NULL pointer dereference at virtual address
00000000 pgd = ffffff800a4e0000
[00000000] *pgd=00000000beffe003[   17.610026] , *pud=00000000beffe003
...
[<ffffff800897fe04>] mtk_smi_enable+0x1c/0xd0
[<ffffff800897fee8>] mtk_smi_larb_get+0x30/0x98
[<ffffff80088edfa8>] mtk_mipicsi0_resume+0x38/0x1b8
[<ffffff8008634f44>] pm_generic_runtime_resume+0x3c/0x58
[<ffffff8008644ff8>] __genpd_runtime_resume+0x38/0x98
[<ffffff8008647434>] genpd_runtime_resume+0x164/0x220
[<ffffff80086372f8>] __rpm_callback+0x78/0xa0
[<ffffff8008637358>] rpm_callback+0x38/0xa0
[<ffffff8008638a4c>] rpm_resume+0x4a4/0x6f8
[<ffffff8008638d04>] __pm_runtime_resume+0x64/0xa0
[<ffffff80088ed05c>] mtk_mipicsi0_probe+0x40c/0xb70
[<ffffff800862cdc0>] platform_drv_probe+0x58/0xc0
[<ffffff800862a514>] driver_probe_device+0x284/0x438
[<ffffff800862a8ac>] __device_attach_driver+0xb4/0x160
[<ffffff8008627d58>] bus_for_each_drv+0x68/0xa8
[<ffffff800862a0a4>] __device_attach+0xd4/0x168
[<ffffff800862a9d4>] device_initial_probe+0x24/0x30
[<ffffff80086291d8>] bus_probe_device+0xa0/0xa8
[<ffffff8008629784>] deferred_probe_work_func+0x94/0xf0
[<ffffff80080f03a8>] process_one_work+0x1d8/0x6e0

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>