cmake: remove obsolete patches

cmake: remove obsolete patches

0001-Disable-use-of-ext2fs-ext2_fs.h-by-cmake-s-internal.patch can be
replaced with two variable assignments to seed the results we want.

0002-CMakeLists.txt-disable-USE_NGHTTP2.patch is not needed anymore as
the vendored curl will disable the use of nghttp2 automatically if it
isn't found.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>