tcl/board/ti_beagle* move to board/beagle/ folder

Move the BeagleBoard.org Foundation boards to it's own folder. This
allows additional support such as BeagleV-Fire and other non TI SoC
vendor support to be subsequently added.

While doing this,
* Use "-" as separator for the file names as recommended
  by coding standards.
* To maintain compatibility, add the non-trivial renames to
  file_renaming.cfg

Change-Id: Ie916c9bf81fc3922bf19ed9ed2db841549d29ca9
Suggested-by: Antonio Borneo <borneo.antonio@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/9204
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: jenkins

tcl/board/beagle/beaglebone-black.cfg

@@ -7,4 +7,4 @@ adapter speed 1000
 
 reset_config trst_and_srst
 
-source [find board/ti_beaglebone-base.cfg]
+source [find board/beagle/beaglebone-base.cfg]

tcl/board/beagle/beaglebone.cfg

@@ -10,4 +10,4 @@ adapter speed 16000
 
 reset_config trst_and_srst
 
-source [find board/ti_beaglebone-base.cfg]
+source [find board/beagle/beaglebone-base.cfg]

tcl/file_renaming.cfg

@@ -20,6 +20,10 @@ set _file_renaming {
 	board/stm32mp13x_dk.cfg			board/st/stm32mp135f-dk.cfg
 	board/stm32mp15x_dk2.cfg		board/st/stm32mp157f-dk2.cfg
 	board/sifive-hifive1-revb.cfg		board/sifive/hifive1-rev-b.cfg
+	board/ti_beagleboard.cfg		board/beagle/beagleboard.cfg
+	board/ti_beagleboard_xm.cfg		board/beagle/beagleboard-xm.cfg
+	board/ti_beaglebone_black.cfg	board/beagle/beaglebone-black.cfg
+	board/ti_beaglebone.cfg			board/beagle/beaglebone.cfg
 	interface/chameleon.cfg			interface/parport/chameleon.cfg
 	interface/flashlink.cfg			interface/parport/flashlink.cfg
 }