newlib: define PATH_MAX and ARG_MAX consistently

Fixes https://github.com/espressif/esp-idf/issues/289.
Fixes https://github.com/espressif/esp-idf/issues/534.

components/newlib/include/limits.h

@@ -142,5 +142,5 @@
 #endif
 
 #ifndef PATH_MAX
-#define PATH_MAX	4096
+#define PATH_MAX	1024
 #endif

components/newlib/include/sys/syslimits.h

@@ -37,7 +37,7 @@
 #ifndef _SYS_SYSLIMITS_H_
 #define _SYS_SYSLIMITS_H_
 
-#define	ARG_MAX			65536	/* max bytes for an exec function */
+#define	ARG_MAX			 4096	/* max bytes for an exec function */
 #ifndef CHILD_MAX
 #define	CHILD_MAX		   40	/* max simultaneous processes */
 #endif