counter: 104-quad-8: Remove reference in Kconfig to 25-bit counter value

Support for 25-bit counter values was removed in commit 4aa3b75c
("counter: 104-quad-8: Fix race condition between FLAG and CNTR reads").
Adjust the Kconfig description of CONFIG_104_QUAD_8 to remove reference
of 25-bit counter values.

Link: https://lore.kernel.org/r/20230410134516.102886-1-william.gray@linaro.org/


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