Documentation: Replace obsolete "driverfs" with "sysfs".

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>

Documentation/pnp.txt

@@ -17,9 +17,9 @@ The User Interface
 ------------------
 	The Linux Plug and Play user interface provides a means to activate PnP devices
 for legacy and user level drivers that do not support Linux Plug and Play.  The 
-user interface is integrated into driverfs.
+user interface is integrated into sysfs.
 
-In addition to the standard driverfs file the following are created in each 
+In addition to the standard sysfs file the following are created in each
 device's directory:
 id - displays a list of support EISA IDs
 options - displays possible resource configurations

Documentation/s390/cds.txt

@@ -133,7 +133,7 @@ During its startup the Linux/390 system checks for peripheral devices. Each
 of those devices is uniquely defined by a so called subchannel by the ESA/390
 channel subsystem. While the subchannel numbers are system generated, each
 subchannel also takes a user defined attribute, the so called device number.
-Both subchannel number and device number cannot exceed 65535. During driverfs
+Both subchannel number and device number cannot exceed 65535. During sysfs
 initialisation, the information about control unit type and device types that 
 imply specific I/O commands (channel command words - CCWs) in order to operate
 the device are gathered. Device drivers can retrieve this set of hardware