mmc: via-sdmmc: Remove set-but-unused variable.

drivers/mmc/host/via-sdmmc.c: In function ‘via_reset_pcictrl’:
drivers/mmc/host/via-sdmmc.c:805:8: warning: variable ‘addrbase’ set but
not used [-Wunused-but-set-variable]

Signed-off-by: Chris Ball <cjb@laptop.org>
Cc: Harald Welte <HaraldWelte@viatech.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>