[MMC] Add mmc_hostname() macro

mmc_hostname() returns a pointer to the hostname for the mmc_host.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index f90f674..3078623 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -97,6 +97,7 @@
 
 #define mmc_priv(x)	((void *)((x) + 1))
 #define mmc_dev(x)	((x)->dev)
+#define mmc_hostname(x)	((x)->host_name)
 
 extern int mmc_suspend_host(struct mmc_host *, pm_message_t);
 extern int mmc_resume_host(struct mmc_host *);