Parity for spl in objcopy removed sections

aosp/3047342 (commit f6fe0e11eb5ffc68e657e2c7e7a472058fe128f4) adds some
flags to have objcopy remove additional debug sections. When building
u-boot in x86_64 mode, it also uses an objcopy command from
`scripts/Makefile.spl` that needs this change applied as well.

Commit created with diagnosing help from rammuthiah@ in finding the CL
with relevant changes.

Bug: b/365955006
Test: tools/bazel run //u-boot:crosvm_x86_64_dist --notoolchain_from_sources
Change-Id: Ife0097a979ae08c6592b762d251aae568b29228d
1 file changed