net: stmmac: rk: replace HIWORD_UPDATE() with GRF_FIELD()

net: stmmac: rk: replace HIWORD_UPDATE() with GRF_FIELD()

Provide GRF_FIELD() which takes the high/low bit numbers of the field
and field value, generates the mask and passes it to FIELD_PREP_WM16.
Replace all HIWORD_UPDATE() instances with this.

No change to produced code on aarch64.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/E1vJbP1-0000000EBqJ-1AjR@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>