Hi Greg,
The following patches are needed in various stable releases to build sparc/sparc64 images with gcc 7.3.0.
v4.4: 56962f8b250a Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
v4.9 and earlier: 0fde7ad71ee3 sparc64: Fix build warnings with gcc 7.
v4.9: 009615ab7fd4 USB: serial: cp210x: use tcflag_t to fix incompatible pointer type
Thanks, Guenter