Fix:
spi.c: In function 'spi_init_r':
spi.c:279:22: warning: variable 'cp' set but not used
[-Wunused-but-set-variable]
spi.c: In function 'spi_xfer':
spi.c:361:22: warning: variable 'cp' set but not used
[-Wunused-but-set-variable]
Signed-off-by: Wolfgang Denk <wd@denx.de>