hw/char/pl011: Replace magic values by register field definitions

0x400 is Data Register Break Error (DR_BE),
0x10 is Line Control Register Fifo Enabled (LCR_FEN)
and 0x1 is Send Break (LCR_BRK).

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230522153144.30610-7-philmd@linaro.org>
1 file changed