split startup.tcl file across modules

Moves definitions for each layer into their own file, eliminating
layering violations in the built-in TCL code.  Updates src/Makefile.am
rules to include all files in the final startup.tcl input file, and
others Makefile.am rules to distribute the new files in our packages.

src/flash/startup.tcl

@@ -0,0 +1,16 @@
+# Defines basic Tcl procs for OpenOCD flash module
+
+# Show flash in human readable form
+# This is an example of a human readable form of a low level fn
+proc flash_banks {} {
+	set i 0
+	set result ""
+	foreach {a} [ocd_flash_banks] {
+		if {$i > 0} {
+			set result "$result\n"
+		}
+		set result [format "$result#%d: %s at 0x%08x, size 0x%08x, buswidth %d, chipwidth %d" $i $a(name) $a(base) $a(size) $a(bus_width) $a(chip_width)]
+		set i [expr $i+1]
+	}
+	return $result
+}