Revert "Revert "fix wrong build flags setup and add more build flags""

This reverts commit 19fa33906916d9ec76bfa49fdfecf8fa9ce56fd8.
Revert "defconfig update"

This reverts commit 46682a59ed0f41b9a169510a7e8115e4dc2538ca.
Revert "Makefile: adding config variable for Ofast compilation"

This reverts commit 567cc42442812176995751634460724f4c4e80a9.
Revert "Makefile: enable graphite loop optimization"

This reverts commit edc92762b2899e8903a1b7dacef9a87d021d75df.
Revert "Makefile: improve build flags"

This reverts commit 53ede016d9da0beae953f80982ccee13f5a69a83.
Revert "fix wrong build flags setup and add more build flags"

This reverts commit b1c31a047c01de23a7756d44585bdc3276af31dc.