docs: i2c: i2c-topology: fix typo

"intension" should have probably been "intention", however "intent" seems
even better.

Reported-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>