drivers: i3c: i3c_dw: make transfer timeout a Kconfig option

The current value of 1s is much too long, default to 100ms instead
which is enough for even a large 4kB FM I2C transfer to finish in
time let alone a typical I3C transfer. Make this configurable in
case projects want to tune this.

Signed-off-by: Corey Wharton <xodus7@cwharton.com>