gdb: Fixup dependencies and add USE_gdb_tui flag
gdb: Fixup dependencies and add USE_gdb_tui flag

Add USE_gdb_tui flag to enable gdb TUI support (curses based user
interface).  Default value is enabled on all platforms except mingw, where
it is disabled for now.  When pdcurses is added, it should also be enabled
by default for mingw.

Signed-off-by: Esben Haabendal <c5ba3f1141bb30a64dd6c7e6726a53a85adc9442@prevas.dk>

moths/base,kimrhh/base,kimrhh/base,esben/base,hundeboll/base,esben/base,sknsean/base,esben/base,moths/base,sknsean/base,hundeboll/base,moths/base,moths/base,oe-lite/base,hundeboll/base,hundeboll/base,sknsean/base,esben/base,sknsean/base,moths/base,oe-lite/base,oe-lite/base,esben/base,oe-lite/base,kimrhh/base,hundeboll/base,kimrhh/base,oe-lite/base,esben/base,moths/base,oe-lite/base,kimrhh/base,kimrhh/base,sknsean/base,hundeboll/base,sknsean/base