MMC SD fs boot partition config coding style and proper description

CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION ought to be called
CONFIG_SYS_MMCSD_FS_BOOT_PARTITION to keep it consistent with other config
options such as: CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR.

In addition, it is not related to raw mode booting but to fs mode instead.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/include/configs/imx6_spl.h b/include/configs/imx6_spl.h
index 5a5f940..9f4e226 100644
--- a/include/configs/imx6_spl.h
+++ b/include/configs/imx6_spl.h
@@ -46,7 +46,7 @@
 #if defined(CONFIG_SPL_MMC_SUPPORT)
 #define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR	138 /* offset 69KB */
 #define CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS	800 /* 400 KB */
-#define CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION	1
+#define CONFIG_SYS_MMCSD_FS_BOOT_PARTITION	1
 #define CONFIG_SYS_MONITOR_LEN  (CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS/2*1024)
 #endif