selftests/powerpc/pmu: Link ebb tests with -no-pie

selftests/powerpc/pmu: Link ebb tests with -no-pie

BugLink: https://bugs.launchpad.net/bugs/1812805
When running the ebb tests after building on a ppc64le Ubuntu machine:

 $ pmu/ebb/reg_access_test: error while loading shared libraries:
 R_PPC64_ADDR16_HI reloc at 0x000000013a965130 for symbol `' out of
 range

This is because the Ubuntu toolchain builds has PIE enabled by default.
Change it to be always off instead.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit 98415da03ae6559dc62899fd31e55e194779c45b)
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Acked-by: Kleber Souza <kleber.souza@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>