package/udpcast: move comment around, to keep proper indentation

In Kconfig, when there is an item (like a comment) between a symbol and
its dependees, then the indentation is not in effect.

Move the symbol to the top of the file to guarantee the indentation in
menuconfig.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

package/udpcast/Config.in

@@ -1,3 +1,7 @@
+comment "udpcast needs a toolchain w/ threads"
+	depends on BR2_USE_MMU
+	depends on !BR2_TOOLCHAIN_HAS_THREADS
+
 config BR2_PACKAGE_UDPCAST
 	bool "udpcast"
 	depends on BR2_TOOLCHAIN_HAS_THREADS
@@ -8,10 +12,6 @@ config BR2_PACKAGE_UDPCAST
 
 	  http://www.udpcast.linux.lu/
 
-comment "udpcast needs a toolchain w/ threads"
-	depends on BR2_USE_MMU
-	depends on !BR2_TOOLCHAIN_HAS_THREADS
-
 if BR2_PACKAGE_UDPCAST
 
 menu "udpcast tools selection"