drm/arm/hdlcd: Use devm_platform_ioremap_resource()

According to commit 7945f929

 ("drivers: provide
devm_platform_ioremap_resource()"), convert platform_get_resource(),
devm_ioremap_resource() to a single call to Use
devm_platform_ioremap_resource(), as this is exactly what this function
does.

Since 'struct platform_device *pdev = to_platform_device(drm->dev)',
'drm->dev' is equivalent to 'pdev->deva'.

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230314080231.20212-1-yang.lee@linux.alibaba.com