soc: imx93: a55: add empty soc.h

Some drivers need header file soc.h, according to Zephyr SoC Porting Guide
soc.h must be provided for each SoC, so created an empty one.

Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>

soc/nxp/imx/imx9/imx93/a55/soc.h

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _SOC_NXP_IMX_IMX93_A55_SOC_H_
+#define _SOC_NXP_IMX_IMX93_A55_SOC_H_
+
+
+#endif /* _SOC_NXP_IMX_IMX93_A55_SOC_H_ */