soc: it8xxx2/linker: Make h2ram_pool behind the CONFIG_ESPI_IT8XXX2 option

The .h2ram_pool linker section was previously always included, even on
platforms that do not enable eSPI. This caused unnecessary memory
reservation in the RAMABLE_REGION for non-eSPI configurations.

Add a CONFIG_ESPI_IT8XXX2 guard around the .h2ram_pool section definition
so that it is only included when eSPI support is enabled.

Signed-off-by: Tim Lin <tim2.lin@ite.corp-partner.google.com>

Author: GTLin08

soc/ite/ec/it8xxx2/linker.ld

@@ -441,6 +441,7 @@ SECTIONS
 
     __data_region_end = .;
 
+#ifdef CONFIG_ESPI_IT8XXX2
 	SECTION_DATA_PROLOGUE(.h2ram_pool,(NOLOAD),)
 	{
 		/*
@@ -456,6 +457,7 @@ SECTIONS
 		_h2ram_pool_end = .;
 	}  GROUP_DATA_LINK_IN(RAMABLE_REGION, RAMABLE_REGION)
 	_h2ram_pool_size = ABSOLUTE(_h2ram_pool_end - _h2ram_pool_start);
+#endif
 
 	__kernel_ram_end = .;
 	__kernel_ram_size = __kernel_ram_end - __kernel_ram_start;