linker: riscv: Relocate .eh_frame symbol

The .eh_frame symbol was causing __data_rom_start to contain the wrong
offset into the ROM, resulting in corrupt data copied into RAM by
_data_copy(). Fix by placing the .eh_frame in the .text section as is
done in include/arch/x86/linker.ld

Signed-off-by: Nathaniel Graff <nathaniel.graff@sifive.com>

include/arch/riscv32/common/linker.ld

@@ -83,6 +83,7 @@ SECTIONS
 		*(.text)
 		*(".text.*")
 		*(.gnu.linkonce.t.*)
+		*(.eh_frame)
 	} GROUP_LINK_IN(ROMABLE_REGION)
 
     _image_text_end = .;