mmc: sdhci: convert sdhci_set_uhs_signaling() into a library function

Add sdhci_set_uhs_signaling() and always call the set_uhs_signaling
method.  This avoids quirks being added into sdhci_set_uhs_signaling().

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>
[Ulf Hansson] Resolved conflict
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c
index db5257b..3c0f3c0 100644
--- a/drivers/mmc/host/sdhci-pxav2.c
+++ b/drivers/mmc/host/sdhci-pxav2.c
@@ -116,6 +116,7 @@
 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
 	.set_bus_width = pxav2_mmc_set_bus_width,
 	.reset         = pxav2_reset,
+	.set_uhs_signaling = sdhci_set_uhs_signaling,
 };
 
 #ifdef CONFIG_OF