powerpc/82xx: Remove pq2_init_pci

Commit 859b21a0 ("powerpc: drop PowerQUICC II Family ADS platform
support") removed last user of pq2_init_pci.

Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/8b2db7c3c2c346aa8aa49507415c360d441e5bf5.1692259498.git.christophe.leroy@csgroup.eu