soc: qcom: remove warning msg in msm_l2_erp_irq()

smp_call_function_many() used in msm_l2_erp_irq() gives
a warning when called with interrupt disabled. Instead use
smp_call_function_single_async().

Change-Id: I03cdc0cc07281460a33abe9b09ae0f06590029aa
Signed-off-by: Puja Gupta <pujag@codeaurora.org>