counter: ti-eqep: remove unused struct member

Since commit 8817c2d0 ("counter: ti-eqep: Convert to counter_priv()
wrapper") the counter field in struct ti_eqep_cnt is not used anymore.
Remove it.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Judith Mendez <jm@ti.com>
Link: https://lore.kernel.org/r/20240609-ti-eqep-cleanup-v1-1-9d67939c763a@baylibre.comSigned-off-by: William Breathitt Gray <wbg@kernel.org>

drivers/counter/ti-eqep.c

@@ -122,7 +122,6 @@ enum ti_eqep_count_func {
 };
 
 struct ti_eqep_cnt {
-	struct counter_device counter;
 	struct regmap *regmap32;
 	struct regmap *regmap16;
 };