Support for 16 MPU regions was added to Cortex-M33, M35P, M55 and M85
ports was added but the compile time error check was not removed. This
results in compilation error when 16 MPU regions are used. This PR
removes the not needed compile time error check.
It was reported here - https://forums.freertos.org/t/cortex-m55-and-16-region-mpu-support/21470.
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>