Remove obsolete patches after NDK updated to r23

Some of the patches are not required as currently we are using Android
NDK 23 in Chromium.

Test(compilation):
    1) Reverse apply the obsolete patches
        patch -R -p1 < patches/0002-disable-ftw.patch
        patch -R -p1 < patches/0004-gnu-basename.patch
        patch -R -p1 < patches/0006-memory-process-vm-readv.patch
    2) Build `chrome_modern_public_bundle` successfully

Bug: 1140633
Change-Id: I24f0205c7e8fdfd2e0dc2e7db8297ea2560f3e1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/third_party/libunwindstack/+/3876186
Reviewed-by: Mike Wittman <wittman@chromium.org>
14 files changed