IOMUX: Refactor iomux_doenv() in order to increase readability

Refactor iomux_doenv() a bit in order to increase readability.
There is no change in code generation on x86.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed