PCI/VGA: Correct vga_update_device_decodes() parameter type

Previously vga_update_device_decodes() took "int new_decodes", but the
callers pass "unsigned int new_decodes".  Correct the
vga_update_device_decodes() parameter type to "unsigned int" to match.

In vga_arbiter_notify_clients(), the return from vgadev->set_decode() is
"unsigned int" but was stored as "uint32_t new_decodes".  Correct the
new_decodes type to "unsigned int".

[bhelgaas: use correct type for ->set_decode() return, commit log]
Link: https://lore.kernel.org/r/20230808223412.1743176-5-sui.jingfeng@linux.dev


Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>