pw_digital_io_mcuxpresso: Remove RT595 size def

We can rely on template deduction of the std::array parameters instead
of hardcoding the RT595 specific sizes.

Test: Builds on downstream project
Test: static_assert(kGpioClocks.size() == 8) builds
Change-Id: Ib26b7af9b4a35cd9ef8e32db693c29991586ec23
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/178353
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Austin Foxley <afoxley@google.com>
Commit-Queue: Rishi Sikka <rishisikka@google.com>
diff --git a/pw_digital_io_mcuxpresso/digital_io.cc b/pw_digital_io_mcuxpresso/digital_io.cc
index bae7f60..c599d58 100644
--- a/pw_digital_io_mcuxpresso/digital_io.cc
+++ b/pw_digital_io_mcuxpresso/digital_io.cc
@@ -26,11 +26,8 @@
 namespace pw::digital_io {
 namespace {
 
-constexpr size_t kRt595ClockNum = 8;
-constexpr size_t kRt595ResetNum = 8;
-
-constexpr std::array<clock_ip_name_t, kRt595ClockNum> kGpioClocks = GPIO_CLOCKS;
-constexpr std::array<reset_ip_name_t, kRt595ResetNum> kGpioResets = GPIO_RSTS_N;
+constexpr std::array kGpioClocks = GPIO_CLOCKS;
+constexpr std::array kGpioResets = GPIO_RSTS_N;
 
 }  // namespace