Re-applies the target architecture and FPU changes fromcc50788(reverted on dev ina3b718c) on top of the soft-float baseline: Cortex-M7 with hardware VFPv5 FPU (-mfloat-abi=hard), plus uClibc-ng built with UCLIBC_HAS_FPU=y. Hard-float support and the resulting device-side fixes are being developed here rather than on dev directly.