Update ACL pin to 639f0f665b4346d287014adc99e14a8497aadf18
Update ACL pin to 639f0f665b4346d287014adc99e14a8497aadf18

Signed-off-by: Nikhil Raj <70dde441576cd8b053dd4c3a595f3f0b9c7a63a3@arm.com>
Change-Id: I88ccfe33e6149d12a06235fcddefb1cdf543d26a

ARM-software/armnn,ARM-software/armnn,ARM-software/armnn