arch/powerpc: Remove .interp section in vmlinux

When building with CONFIG_RELOCATABLE, there is a .interp section
which contains the name of the expected ELF interpreter:

Contents of section .interp:
 c0000000021c1bac 2f757372 2f6c6962 2f6c642e 736f2e31  /usr/lib/ld.so.1
 c0000000021c1bbc 00                                   .

That information is useless and even likely wrong. Remove it.

Link: https://github.com/linuxppc/issues/issues/434


Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/eeaf8fd6628a75d19872ab31cf7e7179e2baef5e.1751366959.git.christophe.leroy@csgroup.eu