tests: arch: arm: arm_irq_vector_table: Microchip MEC build fix

Running twister with plaform Microchip mec_assy6941/<variant_name>
builds the arm_irq_vector_table test. Microchip mec_assy6941 boards
all use a 32-bit 32 KHz timer for the kernel. The test build fails
due to any board using a custom kernel timer driver requires the
test to include a chip specific interrupt table. We don't want to
exclude the test. The MEC chips include Cortex-M4 SysTick. We added
board overlays to the test turning off the 32KHz timer and enabling
ARM SysTick. The test now builds.

Signed-off-by: Scott Worley <scott.worley@microchip.com>