tests: arch: arm: irq_vector_table Add correct ISR table for iMX.RT SOCs

RT1xxx SOCs using the GPT timer require a custom ISR table for the arm
irq_vector_table test, since they use a custom system timer implemented
using the GPT peripheral. Implement the required vector tables within
the irq_vector_table test to enable it to run.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>