counter: chrdev: remove a typo in header file comment

Replace COUNTER_COUNT_SCOPE that doesn't exist by the defined
COUNTER_SCOPE_COUNT.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20230829134029.2402868-3-fabrice.gasnier@foss.st.com


Signed-off-by: William Breathitt Gray <william.gray@linaro.org>