timer.c: assignment of unsigned to signed
timer.c: assignment of unsigned to signed

The passed in argument or returned value was defined as uint32_t
odp_timer_t, however the the local variable id was defined as an int.

Signed-off-by: Mike Holmes <ed44c09f4d7f698f5510adc894a872c73e08c8bd@linaro.org>

mike-holmes-linaro/odp,dkrot/odp,rsalveti/odp,dkrot/odp,rsalveti/odp,mike-holmes-linaro/odp,ravineet-singh/odp,kalray/odp-mppa,rsalveti/odp,nmorey/odp,kalray/odp-mppa,erachmi/odp,mike-holmes-linaro/odp,nmorey/odp,robbieking64/odp-crypto,rsalveti/odp,robbieking64/odp-crypto,kalray/odp-mppa,erachmi/odp,nmorey/odp,dkrot/odp,kalray/odp-mppa,ravineet-singh/odp,kalray/odp-mppa,dkrot/odp,robbieking64/odp-crypto,robbieking64/odp-crypto,erachmi/odp,nmorey/odp,rsalveti/odp,ravineet-singh/odp,kalray/odp-mppa,ravineet-singh/odp,erachmi/odp,kalray/odp-mppa,mike-holmes-linaro/odp