wifi: wilc1000: set atomic flag on kmemdup in srcu critical section

In order to prepare wilc1000 driver switch from SRCU to RCU, make sure that
allocators are provided with the GFP_ATOMIC flag when called in a critical
read section.

Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240410-wilc_srcu_to_rcu-v1-1-a9ff5b10feaa@bootlin.com