[uracoli-devel] Fixed SPI initialization issue

[Daniel Thiele]

Dear developers,
the SPI initialization issue i complained about yesterday is fixed.
I ignored the fact, that the TRX SPI select signal is no more  
identical to SPI SS signal which is used to decide between SPI  
Master/Slave mode (by AVR hardware). SPI SS was floating to GND and  
SPI unit switched to Slave mode. I enabled the pullup on SS line  
(although this is never used) in board_muse231.h.

b.t.w: first successful frame transmission (xmpl_trx_tx_muse231.hex) for Muse!

best regards
Daniel