PCI/ACPI: Fix acpi_pci_osc_control_set() kernel-doc comment

Add the description of @support and remove @req in
acpi_pci_osc_control_set() kernel-doc comment to remove warnings found
by running scripts/kernel-doc, which is caused by using 'make W=1'.

drivers/acpi/pci_root.c:337: warning: Excess function parameter 'req'
description in 'acpi_pci_osc_control_set'
drivers/acpi/pci_root.c:337: warning: Function parameter or member
'support' not described in 'acpi_pci_osc_control_set'

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Fixes: 6bc779ee ("PCI/ACPI: Check for _OSC support in acpi_pci_osc_control_set()")
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>