In commit 513b20ffd328934c58af169e2bce0c0a01eddee2 the SPI API was changed to
power up an configure the SPI bus on spi_acquire(). Sadly, the lpc2387 SPI
apparently needs to be reconfigured after each power up. This commit moves
the initialization code required after each power up from spi_init() to
spi_acquire().