package/freescale-imx/kernel-module-imx-gpu-viv: bump to version 6.4.0.p1.0

package/freescale-imx/kernel-module-imx-gpu-viv: bump to version 6.4.0.p1.0

This package has been tested on Nitrogen8M with the following commands:
 # modprobe galcore
 # cd /usr/share/examples/viv_samples/vdk/
 # ./tutorial7

Also update the help text as we shouldn't specify a kernel revision. It
is just that this module isn't meant for mainline kernel, only its NXP
forked version.

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>