mmc: sdhci-bcm-kona: Remove unneeded version.h inclusion

version.h header inclusion is not necessary as detected by
versioncheck.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Christian Daudt <csd@broadcom.com>
mmc: sdhci-bcm-kona: Staticize sdhci_bcm_kona_card_event

sdhci_bcm_kona_card_event is referenced only in this file.
Make it static.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Christian Daudt <csd@broadcom.com>