boards: shields: rk055hdmipi4ma0: fix GT911 identifier in RT595 overlay

In 42c6f331 (boards: stop using kscan for LVGL touch input), GT911
node label was renamed for rk055hdmipi4ma0 shield. The node label rename
was missed in the RT595 EVK overlay, fix this.

Fixes #69302

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>