Add processor target (cortex-m33), linker script (2048K flash, 768K RAM),
and arduino-uno-q board target. Runtime initializes 160MHz clock via PLL1
from HSI16, with PWR Range 1 and EPOD booster.
Also add psctype abstraction for timer PSC register width, needed because
the U5 SVD defines PSC as a 16-bit register.
deadprogram