riscv: Move address classification info types to riscv-protos.h

riscv: Move address classification info types to riscv-protos.h

enum riscv_address_type and struct riscv_address_info are used
to store address classification information. Let's move this types
into our common header file in order to share them with other
compilation units.

This is a non-functional change without any intendet side-effects.

gcc/ChangeLog:

	* config/riscv/riscv-protos.h (enum riscv_address_type):
	New location of type definition.
	(struct riscv_address_info): Likewise.
	* config/riscv/riscv.cc (enum riscv_address_type):
	Old location of type definition.
	(struct riscv_address_info): Likewise.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>