soc: nxp: imxrt11xx: support configuration of ARM PLL

Add support for configuration of the ARM PLL on the iMXRT1170/1160
series SOCs. This PLL is used to generate the M7 core frequency, and is
an integer pll. Provide default configurations for the RT1160 and RT1170
targeting 600MHz and 1GHz respectively.

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