Revert "spi: spi-axi-spi-engine: Use helper function devm_clk_get_enabled()"

This reverts commit aec8b34e which is
commit a08199b3 upstream.
It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I39e3444570da20fabea97bb89a95cc5c248ebecf
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>