ata: ahci_octeon: Remove unnecessary include

asm/octeon/octeon.h already includes asm/bitfield.h, so there is no need
to include this latter file in ahci_octeon.c as the code does not
directly use the __BITFIELD_FIELD macro defined in it.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

drivers/ata/ahci_octeon.c

@@ -16,7 +16,6 @@
 #include <linux/of_platform.h>
 
 #include <asm/octeon/octeon.h>
-#include <asm/bitfield.h>
 
 #define CVMX_SATA_UCTL_SHIM_CFG		0xE8