apr: clean up the patches + enable LFS

apr: clean up the patches + enable LFS

- removes 001-autoconf-compat.patch:
  Looks like this was meant as a workaround for a libtool issue. But it
  doesn't appear to be needed anymore.
- removes 101-fix_apr_time_now.patch:
  Mentioned in https://dev.openwrt.org/ticket/9287, meant as a fix, but
  issue was fixed differently in the end (by activating LFS).
- removes 201-upgrade-and-fix-1.5.1.patch:
  This is a cross-compile fix. This patch gets replaced by
  001-cross-compile.patch from buildroot project. The latter was sent
  upstream by buildroot and is in line with the patch used by OpenWrt
  for the apache package.
- adds 002-sys-param-h.patch:
  Fix PATH_MAX detection by including sys/param.h if available. Also
  from buildroot.

Additionally configure variables found in buildroot package are added.
These also enable LFS support. This was previously done (in OpenWrt) by
defining _LARGEFILE64_SOURCE in TARGET_CPPFLAGS. But the configure
variable is cleaner (and easier to follow).

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>