powerpc/64e: Remove unnecessary #ifdef CONFIG_PPC_FSL_BOOK3E

CONFIG_PPC_BOOK3E_64 implies CONFIG_PPC_FSL_BOOK3E so no need of
additional #ifdefs in files built exclusively for CONFIG_PPC_BOOK3E_64.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/df16255c13b63b0221c9be63b94a6864bed22c12.1663606875.git.christophe.leroy@csgroup.eu