openocd: esp32: gdb init command update

flushregs alias is deprecated, so it was replaced by the command:
"maintenance flush register-cache"

Signed-off-by: Marcio Ribeiro <[email protected]>

Author: wmrsouza

boards/common/esp32.board.cmake

@@ -6,7 +6,7 @@ board_set_debugger_ifnset(openocd)
 board_runner_args(openocd  --no-init --no-halt --no-targets --no-load)
 board_runner_args(openocd  --gdb-init "set remote hardware-watchpoint-limit 2")
 
-board_runner_args(openocd  --gdb-init "flushregs")
+board_runner_args(openocd  --gdb-init "maintenance flush register-cache")
 board_runner_args(openocd  --gdb-init "mon reset halt")
 board_runner_args(openocd  --gdb-init "thb main")