Add the RX machine internally simulated in GDB.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[PMD: Use TYPE_RX62N_CPU, use #define for RX62N_NR_TMR/CMT/SCI,
 renamed CPU -> MCU, device -> microcontroller]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200224141923.82118-18-ysato@users.sourceforge.jp>
[PMD: Split of MCU, rename gdbsim, Add gdbsim-r5f562n7/r5f562n8]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>