PCI: rcar: Pull bus clock enable/disable from rcar_pcie_get_resources()

The rcar_pcie_get_resources() is another misnomer with a side effect.
The function does not only get resources, but also enables/disables bus
clock. This is forgotten in the probe() function though and if anything
in probe() fails after rcar_pcie_get_resources() is called, the bus
clock are never disabled.

This patch pulls the clock handling out of the rcar_pcie_get_resources()
and enables clock after all the resources were requested. Moreover, this
patch also always disables the clock in case of failure.

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org