drm/appletbdrm: Use kvzalloc for big allocations

drm/appletbdrm: Use kvzalloc for big allocations

This driver is attached to a ~2000x80 screen, which is a lot more than
a single page. This causes out of memory errors in some rare cases.

Reported-by: soopyc <cassie@soopy.moe>
Closes: https://github.com/t2linux/fedora/issues/51
Signed-off-by: Sasha Finkelstein <k@chaosmail.tech>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Aditya Garg <gargaditya08@live.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 0670c2f56e45 ("drm/tiny: add driver for Apple Touch Bars in x86 Macs")
Cc: <stable@vger.kernel.org> # v6.15+
Link: https://patch.msgid.link/20260420-x86-tb-vmalloc-v1-1-7757ff657223@chaosmail.tech