[tosa] improved legalization for leaky_relu
sorry, I messed up, pulled in another commit unintentionally. will abandon this PR and do over
using max/min instead of select

Signed-off-by: Tai Ly [tai.ly@arm.com](mailto:tai.ly@arm.com)
Change-Id: I6e3929873ea2b1f12fe635b4e953c14ed5bdf526