plat: common: include "bl_common.h" from plat_spmd_manifest.c
plat: common: include "bl_common.h" from plat_spmd_manifest.c

This patch includes the bl_common.h from plat_spmd_manifest.c to
fix the following compilation errors

<snip>
plat/common/plat_spmd_manifest.c: In function 'plat_spm_core_manifest_load':
plat/common/plat_spmd_manifest.c:130:18: error: implicit declaration of function 'page_align' [-Werror=implicit-function-declaration]
  130 |  pm_base_align = page_align(pm_base, UP);
      |                  ^~~~~~~~~~
plat/common/plat_spmd_manifest.c:130:38: error: 'UP' undeclared (first use in this function); did you mean 'UL'?
  130 |  pm_base_align = page_align(pm_base, UP);
      |                                      ^~
      |                                      UL
plat/common/plat_spmd_manifest.c:130:38: note: each undeclared identifier is reported only once for each function it appears in
plat/common/plat_spmd_manifest.c:146:38: error: 'DOWN' undeclared (first use in this function)
  146 |  pm_base_align = page_align(pm_base, DOWN);
      |                                      ^~~~
cc1: all warnings being treated as errors
<snip>

Signed-off-by: Varun Wadekar <517ae08f01cae398dbba5bef5ba1750f384c6daf@nvidia.com>
Change-Id: Ib8edb36c6a80a23df2462e708c513c966aab1fef

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware