* changes: docs: describe the new warning levels build: add -Wunused-const-variable=2 to W=2 build: include -Wextra in generic builds docs(porting-guide): update a reference fix(st-usb): replace redundant checks with asserts fix(brcm): add braces around bodies of conditionals fix(renesas): align incompatible function pointers fix(zynqmp): remove redundant api_version check fix: remove old-style declarations fix: unify fallthrough annotations
Manish Pandey