wifi: wilc1000: add missing read critical sections around vif list traversal

Some code manipulating the vif list is still missing some srcu_read_lock /
srcu_read_unlock, and so can trigger RCU warnings:

=============================
WARNING: suspicious RCU usage
6.8.0-rc1+ #37 Not tainted
-----------------------------
drivers/net/wireless/microchip/wilc1000/hif.c:110 RCU-list traversed without holding the required lock!!
[...]
stack backtrace:
CPU: 0 PID: 6 Comm: kworker/0:0 Not tainted 6.8.0-rc1+ #37
Hardware name: Atmel SAMA5
Workqueue: events sdio_irq_work
 unwind_backtrace from show_stack+0x18/0x1c
 show_stack from dump_stack_lvl+0x34/0x58
 dump_stack_lvl from wilc_get_vif_from_idx+0x158/0x180
 wilc_get_vif_from_idx from wilc_network_info_received+0x80/0x48c
 wilc_network_info_received from wilc_handle_isr+0xa10/0xd30
 wilc_handle_isr from wilc_sdio_interrupt+0x44/0x58
 wilc_sdio_interrupt from process_sdio_pending_irqs+0x1c8/0x60c
 process_sdio_pending_irqs from sdio_irq_work+0x6c/0x14c
 sdio_irq_work from process_one_work+0x8d4/0x169c
 process_one_work from worker_thread+0x8cc/0x1340
 worker_thread from kthread+0x448/0x510
 kthread from ret_from_fork+0x14/0x28

Fix those warnings by adding the needed lock around the corresponding
critical sections

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Co-developed-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240215-wilc_fix_rcu_usage-v1-4-f610e46c6f82@bootlin.com