defconfig: sdxlemur: Enable CONFIG_SPMI_MSM_PMIC_ARB{_DEBUG}

Enable SPMI debug bus driver which is useful for writing to PMIC
peripheral registers over debug bus on devices when the fuse is
not blown. While at it, enable CONFIG_SPMI_MSM_PMIC_ARB as well
explicitly though it's selected for sdxlemur already.

Change-Id: I8d04c96efcdb089f8950e57fd1b152cd1cc5a84f
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>