busybox: adjust configuration to add fancy options to the sleep applet

Set CONFIGURE_FEATURE_FANCY_SLEEP and CONFIG_FEATURE_FLOAT_SLEEP so that sleep accept floating point arguments.
This add 492 bytes to the busybox binary compiled for arm or 2748 bytes when compiled for i386.

Signed-off-by: Sylvain Raybaud <sylvain.raybaud@green-communications.fr>
Reviewed-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/busybox/busybox.config

@@ -273,8 +273,8 @@ CONFIG_SHA256SUM=y
 CONFIG_SHA512SUM=y
 CONFIG_SHA3SUM=y
 CONFIG_SLEEP=y
-# CONFIG_FEATURE_FANCY_SLEEP is not set
-# CONFIG_FEATURE_FLOAT_SLEEP is not set
+CONFIG_FEATURE_FANCY_SLEEP=y
+CONFIG_FEATURE_FLOAT_SLEEP=y
 CONFIG_SORT=y
 CONFIG_FEATURE_SORT_BIG=y
 # CONFIG_SPLIT is not set