riscv: Fix C++ exception handling info linking

The RISC-V architecture linker script was including `cplusplus-ram.ld`
linker script before `__data_region_start`, and this caused the content
of `.gcc_except_table` section to be not copied to the RAM by the
`z_data_copy` function; leading to the C++ exception handling
malfunction.

This commit relocates the `cplusplus-ram.ld` linker script inclusion
such that the contents of the relevant sections are properly copied by
the `z_data_copy` function.

Signed-off-by: Stephanos Ioannidis <[email protected]>

Author: stephanosio

include/arch/riscv/common/linker.ld

@@ -227,7 +227,6 @@ SECTIONS
 	}  GROUP_DATA_LINK_IN(RAMABLE_REGION, RAMABLE_REGION)
 
 #include <linker/common-noinit.ld>
-#include <linker/cplusplus-ram.ld>
 
     SECTION_DATA_PROLOGUE(_DATA_SECTION_NAME,,)
 	{
@@ -271,6 +270,7 @@ SECTIONS
 
 #include <linker/common-ram.ld>
 #include <linker/kobject-data.ld>
+#include <linker/cplusplus-ram.ld>
 
 /* Located in generated directory. This file is populated by the
  * zephyr_linker_sources() Cmake function.