pci: qcom: move device init to subsys_initcall_sync

This patch moves device init call from subsys_initcall to its sync
variant. This is required because most of the dependent regulators
drivers comeup at subsys_initcall level and this will result in defer
probe of this driver. This behaviour will have an side effect of pci
devices being probed at pci_scan_root_bus call, which means before the
bus resources are actually allocated. moving to subsys_initcall_sync
call will ensure that all the subsys_initcall level calls are finished
before invoking the deivce init.

Originally found while testing atl1c driver on IFC6410 board.

[    0.281558] qcom_pcie 1b500000.pci: Failed to get vdd supply
[    0.286396] platform 1b500000.pci: Driver qcom_pcie requests probe deferral
...
[    1.804406] PCI host bridge to bus 0000:00
[    1.806090] pci_bus 0000:00: root bus resource [mem 0x08000000-0x0fdfffff]
[    1.810247] pci_bus 0000:00: root bus resource [io  0xfe00000-0xfefffff]
[    1.817105] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
[    1.824023] pci 0000:00:00.0: [17cb:0101] type 01 class 0xff0000
[    1.832008] pci 0000:00:00.0: supports D1
[    1.837829] pci 0000:00:00.0: PME# supported from D0 D1 D3hot
[    1.842170] PCI: bus0: Fast back to back transfers disabled
[    1.847485] pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[    1.853206] pci 0000:01:00.0: [1969:1083] type 00 class 0x020000
[    1.860920] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x0003ffff 64bit]
[    1.867123] pci 0000:01:00.0: reg 0x18: [io  0x0000-0x007f]
[    1.874105] pci 0000:01:00.0: PME# supported from D0 D1 D2 D3hot D3cold
[    1.879499] PCI: bus1: Fast back to back transfers disabled
[    1.885777] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
[    1.891336] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 01
[    1.898325] atl1c 0000:01:00.0: can't enable device: BAR 0 [mem 0x00000000-0x0003ffff 64bit] not claimed
[    1.904509] atl1c 0000:01:00.0: cannot enable PCI device
[    1.914232] atl1c: probe of 0000:01:00.0 failed with error -22
[    1.919630] pci 0000:00:00.0: BAR 8: assigned [mem 0x08000000-0x080fffff]
[    1.925172] pci 0000:00:00.0: BAR 7: assigned [io  0xfe00000-0xfe00fff]
[    1.932044] pci 0000:01:00.0: BAR 0: assigned [mem 0x08000000-0x0803ffff 64bit]
[    1.938488] pci 0000:01:00.0: BAR 2: assigned [io  0xfe00000-0xfe0007f]

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>