button: qcom-pmic: prettify and standardise button labels

Boards using gpio-keys for volume buttons label them "Volume Down",
let's match that here, and make the power button nicer too.

This simplifies configuring button_cmds in a board-agnostic way.

Tested-by: Danila Tikhonov <danila@jiaxyga.com> # google-sunfish
Tested-by: Jens Reidel <adrian@mainlining.org> # xiaomi-davinci
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250331-qcom-phones-v4-5-f52e57d3b8c6@linaro.org
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
diff --git a/board/qualcomm/dragonboard820c/dragonboard820c.c b/board/qualcomm/dragonboard820c/dragonboard820c.c
index d3333a5..12a9273 100644
--- a/board/qualcomm/dragonboard820c/dragonboard820c.c
+++ b/board/qualcomm/dragonboard820c/dragonboard820c.c
@@ -106,7 +106,7 @@
 	int ret;
 	enum button_state_t state;
 
-	ret = button_get_by_label("pwrkey", &btn);
+	ret = button_get_by_label("Power Button", &btn);
 	if (ret < 0) {
 		printf("Couldn't find power button!\n");
 		return ret;