more tcl/{board,target} cleanup

Remove more remnants of the old "jtag_device" syntax.

Don't [format "%s.cpu" $_CHIPNAME] ... it's needless complexity.

Remove various non-supported "-variant" target options; they're not
needed often at all.

Flag some of the board files as needing to have and use target files
for the TAP and target declarations.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

tcl/board/digi_connectcore_wi-9c.cfg

@@ -4,6 +4,10 @@
 
 reset_config trst_and_srst
 
+# FIXME use some standard target config, maybe create one from this
+#
+#	source [find target/...cfg]
+
 if { [info exists CHIPNAME] } {
    set  _CHIPNAME $CHIPNAME
 } else {
@@ -29,7 +33,7 @@ if { [info exists CPUTAPID ] } {
    set _CPUTAPID 0x07926031
 }
 
-set _TARGETNAME [format "%s.cpu" $_CHIPNAME]
+set _TARGETNAME $_CHIPNAME.cpu
 jtag newtap $_CHIPNAME cpu -irlen 4 -ircapture 0x1 -irmask 0xf -expected-id $_CPUTAPID
 
 jtag_nsrst_delay 200
@@ -40,7 +44,7 @@ jtag_ntrst_delay 0
 # Target configuration
 ######################
 
-target create $_TARGETNAME arm926ejs -endian $_ENDIAN -chain-position $_TARGETNAME -variant arm926ejs
+target create $_TARGETNAME arm926ejs -endian $_ENDIAN -chain-position $_TARGETNAME
 
 $_TARGETNAME configure -event reset-init {
 	mww 0x90600104 0x33313333