pinctrl: aspeed: Add ASPEED_SB_PINCONF() helper

This helper macro is for declaring single bit (SB) mask pinconf,
and is used to prepare for modifying aspeed_pin_config
structure, the aspeed_pin_config structure @bit variable will be
modified to @mask.

This case is common in the AST2400/AST2500 which the mask is a single bit.
Signed-off-by: Johnny Huang <johnny_huang@aspeedtech.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20191202061432.3996-5-andrew@aj.id.auSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/aspeed/pinctrl-aspeed.h

@@ -35,6 +35,13 @@ struct aspeed_pin_config {
 		.drv_data = (void *) &(PIN_SYM(name_)) \
 	}
 
+#define ASPEED_SB_PINCONF(param_, pin0_, pin1_, reg_, bit_) { \
+	.param = param_, \
+	.pins = {pin0_, pin1_}, \
+	.reg = reg_, \
+	.bit = bit_ \
+}
+
 struct aspeed_pinctrl_data {
 	struct regmap *scu;