quark_se: Add shared GDT in RAM memory to linker

A new shared memory has been added to the QMSI bootloader in order to
store the GDT in RAM reliably.

Add this new entry to the QUARK SE C1000 linker script and new kconfig
options:

 * CONFIG_BSP_SHARED_GDT_RAM_ADDR to set the address location
   of the GDT in RAM.

 * CONFIG_BSP_SHARED_GDT_RAM_SIZE to set the size used by the
   GDT in RAM.

Additionally, both BSP_SHARED_RAM_ADDR and BSP_SHARED_RAM_SIZE have been
renamed to BSP_SHARED_RESTORE_INFO_RAM_ADDR and
BSP_SHARED_RESTORE_INFO_SIZE respectively, in order to better resemble
what these options are for. All these configs are available
unconditionally.

Change-Id: I07ee8b440d4a3f5e9bdeb62441ff6a7bd6d4c153
Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Signed-off-by: Bartlomiej Majka <bartlomiejx.majka@intel.com>