pinctrl: mcp23s08: Fix mcp23x17 precious range

On page 23 of the datasheet [0] it says "The register remains unchanged
until the interrupt is cleared via a read of INTCAP or GPIO." Include
INTCAPA and INTCAPB registers in precious range, so that they aren't
accidentally cleared when we read via debugfs.

[0] https://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf

Fixes: 8f38910ba4f6 ("pinctrl: mcp23s08: switch to regmap caching")
Signed-off-by: Thomas Preston <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/pinctrl-mcp23s08.c

···
 };
 
 static const struct regmap_range mcp23x17_precious_range = {
-	.range_min = MCP_GPIO << 1,
+	.range_min = MCP_INTCAP << 1,
 	.range_max = MCP_GPIO << 1,
 };