spmi: pmic-arb: revert "validate type when mapping IRQ"

Validation of the IRQ type was added to spmi pmic-arb, however spmi-mpp
in device tree still uses IRQ_TYPE_NONE. This commit caused the
spmi-mpp probe to fail since platform_irq_count() would return 0.
Correct this by backing out the previous patch.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Fixes: 135ef21a ("spmi: pmic-arb: validate type when mapping IRQ")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>