xtensa: fix z_arch_switch()

This was in the wrong header and declared as a macro instead
of an inline function.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

arch/xtensa/include/kernel_arch_data.h

@@ -51,9 +51,6 @@ extern "C" {
 
 typedef struct __esf __esf_t;
 
-void xtensa_switch(void *switch_to, void **switched_from);
-#define z_arch_switch xtensa_switch
-
 #ifdef __cplusplus
 }
 #endif

arch/xtensa/include/kernel_arch_func.h

@@ -83,6 +83,13 @@ static ALWAYS_INLINE void z_arch_kernel_init(void)
 #endif
 }
 
+void xtensa_switch(void *switch_to, void **switched_from);
+
+static inline void z_arch_switch(void *switch_to, void **switched_from)
+{
+	return xtensa_switch(switch_to, switched_from);
+}
+
 #ifdef __cplusplus
 }
 #endif