ARM: dts: msm: Add mem-attn interrupt configuration for PM8150B

For configuring parallel current measurement, mem-attn interrupt
needs to be enabled as the register write should be done only
on the falling edge of that interrupt and PEEK_MUX is configured
to output ALG active signal on that interrupt. Add the interrupt
configuration to PM8150B FG to allow that.

Change-Id: Ie0ab3c67a80d1798af8cc1076c3a889b4b3beb58
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>