brcmfmac: pcie: Read the console on init and shutdown

This allows us to get console messages if the firmware crashed during
early init, or if an operation failed and we're about to shut down.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220131160713.245637-10-marcan@marcan.st