mmc: sdhci: convert reset into a library function

Rather than having platform_reset_enter/platform_reset_exit methods,
turn the core of the reset handling into a library function which
platforms can call at the appropriate moment in their (new) reset
method.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Markus Pargmann <mpa@pengutronix.de>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

diff --cc drivers/mmc/host/sdhci-acpi.c
Simple merge

diff --cc drivers/mmc/host/sdhci-bcm-kona.c
Simple merge

diff --cc drivers/mmc/host/sdhci-bcm2835.c
Simple merge

diff --cc drivers/mmc/host/sdhci-cns3xxx.c
Simple merge

diff --cc drivers/mmc/host/sdhci-dove.c
Simple merge

diff --cc drivers/mmc/host/sdhci-esdhc-imx.c
Simple merge

diff --cc drivers/mmc/host/sdhci-of-arasan.c
Simple merge

diff --cc drivers/mmc/host/sdhci-of-esdhc.c
Simple merge

diff --cc drivers/mmc/host/sdhci-of-hlwd.c
Simple merge

diff --cc drivers/mmc/host/sdhci-pci.c
Simple merge

diff --cc drivers/mmc/host/sdhci-pltfm.c
Simple merge

diff --cc drivers/mmc/host/sdhci-pxav2.c
Simple merge

diff --cc drivers/mmc/host/sdhci-pxav3.c
Simple merge

diff --cc drivers/mmc/host/sdhci-s3c.c
Simple merge

diff --cc drivers/mmc/host/sdhci-sirf.c
Simple merge

diff --cc drivers/mmc/host/sdhci-spear.c
Simple merge

diff --cc drivers/mmc/host/sdhci-tegra.c
Simple merge

diff --cc drivers/mmc/host/sdhci.c
Simple merge

diff --cc drivers/mmc/host/sdhci.h
Simple merge