ath10k: qmi: Sleep for a while before assigning MSA memory

Unless we sleep for a while before transitioning the MSA memory to WLAN
the MPSS.AT.4.0.c2-01184-SDM845_GEN_PACK-1 firmware triggers a security
violation fairly reliably. Unforutnately recovering from this failure
always results in the entire system freezing.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>