powerpc/fadump: use static allocation for reserved memory ranges

At times, memory ranges have to be looked up during early boot, when
kernel couldn't be initialized for dynamic memory allocation. In fact,
reserved-ranges look up is needed during FADump memory reservation.
Without accounting for reserved-ranges in reserving memory for FADump,
MPIPL boot fails with memory corruption issues. So, extend memory
ranges handling to support static allocation and populate reserved
memory ranges during early boot.

Fixes: dda9dbfe ("powerpc/fadump: consider reserved ranges while releasing memory")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/158737294432.26700.4830263187856221314.stgit@hbathini.in.ibm.com