mtd: hyperbus: rpc-if: Fix RPM imbalance in probe error path

If rpcif_hw_init() fails, Runtime PM is left enabled.

Fixes: b04cc0d9 ("memory: renesas-rpc-if: Add support for RZ/G2L")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/f3070e1af480cb252ae183d479a593dbbf947685.1655457790.git.geert+renesas@glider.be