subsys: disk: Kconfig: add prompt messages for config options

Add prompt messages for config options dependent on DISK_ACCESS_FLASH

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
diff --git a/subsys/disk/Kconfig b/subsys/disk/Kconfig
index 977bb8e..f24ef8c 100644
--- a/subsys/disk/Kconfig
+++ b/subsys/disk/Kconfig
@@ -40,11 +40,13 @@
 
 config DISK_FLASH_START
 	hex
+	prompt "Flash device start address in hex"
 	help
 	  This is start address of the flash to be used as storage backend.
 
 config DISK_FLASH_MAX_RW_SIZE
 	int
+	prompt "Flash device max read-write size in decimal"
 	help
 	  This is the maximum number of bytes that the
 	  flash_write API can accept per invocation.
@@ -52,18 +54,21 @@
 
 config DISK_FLASH_ERASE_ALIGNMENT
 	hex
+	prompt "Flash device erase alignment in hex"
 	help
 	  This is the start address alignment required by
 	  the flash component.
 
 config DISK_ERASE_BLOCK_SIZE
 	hex
+	prompt "Flash device block size in hex"
 	help
 	  This is typically the minimum block size that
 	  is erased at one time in flash storage.
 
 config DISK_VOLUME_SIZE
 	hex
+	prompt "Flash device block size in hex"
 	help
 	  This is the file system volume size in bytes.