fix(intel): update Agilex5 warm reset subroutines

Update the 'plat_get_my_entrypoint' assembly routine to
differentiate between cold reset, warm reset and SMP
secondary boot cores request.
Add secondary core boot request markup in BL31.
Perform CACHE flush/clean ops in case of warm reset request also.

Change-Id: I7d33e362a3a513c60c8333e062ce832aa7facf38
Signed-off-by: Girisha Dengi <girisha.dengi@intel.com>
Signed-off-by: Sieu Mun Tang <sieu.mun.tang@intel.com>
diff --git a/plat/intel/soc/agilex5/bl31_plat_setup.c b/plat/intel/soc/agilex5/bl31_plat_setup.c
index b6fc93e..c090117 100644
--- a/plat/intel/soc/agilex5/bl31_plat_setup.c
+++ b/plat/intel/soc/agilex5/bl31_plat_setup.c
@@ -234,6 +234,9 @@
 	unsigned int pchctlr_new = 0x00;
 	uint32_t boot_core = 0x00;
 
+	/* Store magic number for SMP secondary cores boot */
+	mmio_write_32(L2_RESET_DONE_REG, SMP_SEC_CORE_BOOT_REQ);
+
 	boot_core = (mmio_read_32(AGX5_PWRMGR(MPU_BOOTCONFIG)) & 0xC00);
 	/* Update the p-channel based on cpu id */
 	pch_cpu = 1 << cpu_id;