pinctrl: mediatek: remove unused drv_offset field

The 'drv_offset' member in 'struct mtk_pinctrl_devdata' has been unused
since the driver's inception. Drive strength control for MediaTek
pinctrl drivers is actually configured via 'pin_drv_grp',
making this specific offset field redundant.

Remove the unused field from the common 'mtk_pinctrl_devdata' structure
and its corresponding initialization in the mt8365 driver to clean up
the code and avoid confusion.

Signed-off-by: Akari Tsuyukusa <akkun11.open@gmail.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>

Author: akku1139

drivers/pinctrl/mediatek/pinctrl-mt8365.c

@@ -456,7 +456,6 @@ static const struct mtk_pinctrl_devdata mt8365_pinctrl_data = {
 	.smt_offset = 0x0470,
 	.pullen_offset = 0x0860,
 	.pullsel_offset = 0x0900,
-	.drv_offset = 0x0710,
 	.type1_start = 145,
 	.type1_end = 145,
 	.port_shf = 4,

drivers/pinctrl/mediatek/pinctrl-mtk-common.h

@@ -263,7 +263,6 @@ struct mtk_pinctrl_devdata {
 	unsigned int smt_offset;
 	unsigned int pullen_offset;
 	unsigned int pullsel_offset;
-	unsigned int drv_offset;
 	unsigned int dout_offset;
 	unsigned int din_offset;
 	unsigned int pinmux_offset;