counter/ti-eqep: Fix regmap max_register

counter/ti-eqep: Fix regmap max_register

[ Upstream commit 271b339236e1c0e6448bc1cafeaedcb529324bf0 ]

The values given were the offset of the register after the last
register instead of the actual last register in each range. Fix
by using the correct last register of each range.

Fixes: f213729f6796 ("counter: new TI eQEP driver")
Signed-off-by: David Lechner <david@lechnology.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20201025165122.607866-1-david@lechnology.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>