vhdl: fix expr suffix parsing
vhdl: fix expr suffix parsing

Fix an issue where expressions would not properly try to parse further
suffix expressions. More precisely, the following subtype indication
failed to parse:

	unsigned(C_ADDR_WIDTH-1 downto 0)
	                        ^^^^^^

Fix the issue by inserting the appropriate `parse_expr_suffix` calls.

fabianschuiki/moore,fabianschuiki/moore,fabianschuiki/moore,fabianschuiki/moore,fabianschuiki/moore