brcmfmac: fix sdio suspend and resume

commit 330b4e4b ("brcmfmac: Add wowl support for SDIO devices.")
changed the behaviour by removing the MMC_PM_KEEP_POWER flag for
non-wowl scenario, which needs to be restored. Another necessary
change is to mark the card as being non-removable. With this in place
the suspend resume test passes successfully doing:

 # echo devices > /sys/power/pm_test
 # echo mem > /sys/power/state

Note that power may still be switched off when system is going
in S3 state.

Reported-by: Fu, Zhonghui <&lt;zhonghui.fu@linux.intel.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>