The PHTW selection algorithm implemented in rcsi2_phtw_write_mbps() checks for
lower bound of the interval used to match the desired bandwidth. Use that
in place of the currently used upper bound.

Fixes: 10c08812 ("media: rcar: rcar-csi2: Update V3M/E3 PHTW tables")
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>