Revert "lib/string: use glibc version"

This reverts commit efae49abac3589783a033c195299a5f0bba53ce7.
Revert "lib/memcopy: use glibc version"

This reverts commit ccc4083f622b57f8e6ae4ef3f20d55a9cb5df41a.
Revert "ARM: rwsem: use asm-generic rwsem implementation"

This reverts commit 71c7fe8c39580cca7f34e58ed2f1a32c2dc3153b.
Revert "Revert "lib/string: use glibc version""

This reverts commit a1b2427c3f9303ca5ad292b71970a449887de035.
Revert "Revert "lib/memcopy: use glibc version""

This reverts commit 16804434377fa4b80993a26727513e34ac252a10.
Revert "Revert "ARM: rwsem: use asm-generic rwsem implementation""

This reverts commit b39cf6879dcd7bdf55a85f19035f7b089e38a3f0.