phy: rockchip-emmc: switch to FIELD_PREP_WM16 macro

The era of hand-rolled HIWORD_UPDATE macros is over, at least for those
drivers that use constant masks.

Replace the implementation of the rockchip eMMC PHY driver's
HIWORD_UPDATE macro with hw_bitfield.h's FIELD_PREP_WM16. This makes the
change more easily reviewable.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>

Author: Nicolas Frattaroli

drivers/phy/rockchip/phy-rockchip-emmc.c

@@ -8,6 +8,7 @@
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/hw_bitfield.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -21,7 +22,7 @@
  * only if BIT(x + 16) set to 1 the BIT(x) can be written.
  */
 #define HIWORD_UPDATE(val, mask, shift) \
-		((val) << (shift) | (mask) << ((shift) + 16))
+		(FIELD_PREP_WM16((mask) << (shift), (val)))
 
 /* Register definition */
 #define GRF_EMMCPHY_CON0		0x0