serial: Use bits for UART_LSR_BRK_ERROR_BITS/MSR_ANY_DELTA

Instead of listing the bits for UART_LSR_BRK_ERROR_BITS and
UART_MSR_ANY_DELTA in comment, use them to define instead.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220624205424.12686-4-ilpo.jarvinen@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>