mmc: sdhci: Enhance debug register dump

Add new host operation dump_vendor_regs to provide a
mechanism through which host drivers can dump vendor
specific registers in addition to SDHC registers
during error conditions.

Change-Id: Ifba3ddcb18c3c0917343d99fe58d5ed04b2da871
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
[subhashj@codeaurora.org: fixed minor merge conflict]
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
[xiaonian@codeaurora.org: fix trivial merge conflict]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 99abc38..9afd4a6 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -638,6 +638,7 @@
 	void	(*platform_bus_voting)(struct sdhci_host *host, u32 enable);
 	void	(*toggle_cdr)(struct sdhci_host *host, bool enable);
 	void	(*check_power_status)(struct sdhci_host *host, u32 req_type);
+	void	(*dump_vendor_regs)(struct sdhci_host *host);
 	void	(*voltage_switch)(struct sdhci_host *host);
 	int	(*select_drive_strength)(struct sdhci_host *host,
 					 struct mmc_card *card,