samples: pwm: add sama7g54_ek.overlay file to the blink_pwm sample

The sama7g54-ek has the LEDs those can be driven by GPIO or PWM.

Signed-off-by: Tony Han <tony.han@microchip.com>

Author: TonyHan11

samples/basic/blinky_pwm/boards/sama7g54_ek.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) 2025 Microchip Technology Inc. and its subsidiaries
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ */
+
+&pwmleds {
+	status = "okay";
+};
+
+&pwm {
+	status = "okay";
+};