mark Linux-specific configuration options

PLATFORM_LINUX is used as a dependency for applets or features
which require Linux-specific interfaces.

Signed-off-by: Jeremie Koenig <jk@jk.fr.eu.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/procps/Config.src b/procps/Config.src
index e61de56..1ff6dfd 100644
--- a/procps/Config.src
+++ b/procps/Config.src
@@ -10,6 +10,7 @@
 config FREE
 	bool "free"
 	default y
+	depends on PLATFORM_LINUX #sysinfo()
 	help
 	  free displays the total amount of free and used physical and swap
 	  memory in the system, as well as the buffers used by the kernel.
@@ -104,7 +105,7 @@
 config FEATURE_PS_TIME
 	bool "Enable time and elapsed time output"
 	default y
-	depends on PS && DESKTOP
+	depends on PS && DESKTOP && PLATFORM_LINUX #sysinfo()
 	help
 	  Support -o time and -o etime output specifiers.
 
@@ -200,6 +201,7 @@
 config UPTIME
 	bool "uptime"
 	default y
+	depends on PLATFORM_LINUX #sysinfo()
 	help
 	  uptime gives a one line display of the current time, how long
 	  the system has been running, how many users are currently logged