ncurses: Remove recipe override

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
db: Remove recipe override

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
sysvinit-inittab: Remove postinst package override

* This is not required for MicroBlaze/Zynq

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>