[acpi] Make acpi_find_rsdt() a per-platform method

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/x86/include/bits/acpi.h

@@ -0,0 +1,14 @@
+#ifndef _BITS_ACPI_H
+#define _BITS_ACPI_H
+
+/** @file
+ *
+ * x86-specific ACPI API implementations
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <ipxe/rsdp.h>
+
+#endif /* _BITS_ACPI_H */

src/arch/x86/include/ipxe/rsdp.h

@@ -0,0 +1,18 @@
+#ifndef _IPXE_RSDP_H
+#define _IPXE_RSDP_H
+
+/** @file
+ *
+ * Standard PC-BIOS ACPI RSDP interface
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#ifdef ACPI_RSDP
+#define ACPI_PREFIX_rsdp
+#else
+#define ACPI_PREFIX_rsdp __rsdp_
+#endif
+
+#endif /* _IPXE_RSDP_H */