ns9xxx: let putc autodetect where to write

Now putc writes to the first enabled internal UART.  If there is none
the external UART on the a9m9750dev board is used (if enabled).
Otherwise there is no output.

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

diff --cc include/asm-arm/arch-ns9xxx/uncompress.h
Simple merge