soc/intel/common/gpio: Modify pad_config.pad type from `int` to 'gpio_t'

This patch modifies struct pad_config.pad type from `int` to 'gpio_t'
as pad offset inside GPIO community is unsigned type and also to
maintain parity with `struct gpio_lock_config.pad` type.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I15da8a1aff2d81805ba6584f5cc7e569faf456e1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60773
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com>

src/soc/intel/common/block/include/intelblocks/gpio.h

@@ -66,7 +66,7 @@
 typedef uint32_t gpio_t;
 
 struct pad_config {
-	int		pad;/* offset of pad within community */
+	gpio_t		pad;/* offset of pad within community */
 	uint32_t	pad_config[GPIO_NUM_PAD_CFG_REGS];/*
 			Pad config data corresponding to DW0, DW1,.... */
 };