Remove nested functions from PCI iterators.

Remove nested functions from PCI iterators.

* grub-core/bus/pci.c (grub_pci_iterate): Add hook_data argument,
passed to hook.  Update all callers to pass appropriate hook data.
* grub-core/bus/emu/pci.c (grub_pci_iterate): Likewise.
* include/grub/pci.h (grub_pci_iteratefunc_t): Add data argument.
Remove NESTED_FUNC_ATTR from here and from all users.
(grub_pci_iterate): Update prototype.
* grub-core/bus/cs5536.c (grub_cs5536_find: hook): Make static
instead of nested.  Rename to ...
(grub_cs5536_find_iter): ... this.
* grub-core/kern/efi/mm.c (stop_broadcom: find_card): Likewise.
* grub-core/kern/mips/loongson/init.c (init_pci: set_card):
Likewise.
* grub-core/kern/vga_init.c (grub_qemu_init_cirrus: find_card):
Likewise.
* grub-core/video/bochs.c (grub_video_bochs_setup: find_card):
Likewise.
* grub-core/video/cirrus.c (grub_video_cirrus_setup: find_card):
Likewise.
* grub-core/video/efi_uga.c (find_framebuf: find_card): Likewise.
* grub-core/video/radeon_fuloong2e.c
(grub_video_radeon_fuloong2e_setup: find_card): Likewise.
* grub-core/video/sis315pro.c (grub_video_sis315pro_setup:
find_card): Likewise.
* grub-core/video/sm712.c (grub_video_sm712_setup: find_card):
Likewise.