spi: omap-100k: Remove unused definitions

Remove unused definition which cause the following warnings

drivers/spi/spi-omap-100k.c:73:0: warning: "WRITE" redefined [enabled by default]
include/linux/fs.h:193:0: note: this is the location of the previous definition
drivers/spi/spi-omap-100k.c:74:0: warning: "READ" redefined [enabled by default]
include/linux/fs.h:192:0: note: this is the location of the previous definition

Signed-off-by: Nick Krause <xerofoiffy@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>