debug/gdb: cleanup (remove) the static ncurses build

ncurses is built solely for the sake of building a native gdb.
The user should not rely on this library to build his/her userland,
but should rather build his/her own. So we remove it from the
sysroot after we successfully build the native gdb.

 # ia64 specific config options

 # depends on EXPERIMENTAL

 config ARCH_ia64

     select ARCH_USE_MMU

     select ARCH_64

     select ARCH_SUPPORTS_BOTH_ENDIAN

     help

       The ia64 architecture, as defined by:

         http://www.intel.com/design/itanium/arch_spec.htm