drm/irq: Ditch DRIVER_IRQ_SHARED

This is only used by drm_irq_install(), which is an optional helper.
For legacy pci devices this is required (due to interrupt sharing without
msi/msi-x), and just making this the default exactly matches the behaviour
of all existing drivers using the drm_irq_install() helpers. In case that
ever becomes wrong drivers can roll their own irq handling, as many
drivers already do (for other reasons like needing a threaded interrupt
handler, or having an entire pile of different interrupt sources).

v2: Rebase

v3: Improve commit message (Emil)

Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129104248.26607-3-daniel.vetter@ffwll.ch
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 0760a1d..ca46a45 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -100,20 +100,20 @@ enum drm_driver_feature {
 	 * Set up DRM AGP support, see drm_agp_init(), the DRM core will manage
 	 * AGP resources. New drivers don't need this.
 	 */
-	DRIVER_USE_AGP			= BIT(24),
+	DRIVER_USE_AGP			= BIT(25),
 	/**
 	 * @DRIVER_LEGACY:
 	 *
 	 * Denote a legacy driver using shadow attach. Do not use.
 	 */
-	DRIVER_LEGACY			= BIT(25),
+	DRIVER_LEGACY			= BIT(26),
 	/**
 	 * @DRIVER_PCI_DMA:
 	 *
 	 * Driver is capable of PCI DMA, mapping of PCI DMA buffers to userspace
 	 * will be enabled. Only for legacy drivers. Do not use.
 	 */
-	DRIVER_PCI_DMA			= BIT(26),
+	DRIVER_PCI_DMA			= BIT(27),
 	/**
 	 * @DRIVER_SG:
 	 *
@@ -121,7 +121,7 @@ enum drm_driver_feature {
 	 * scatter/gather buffers will be enabled. Only for legacy drivers. Do
 	 * not use.
 	 */
-	DRIVER_SG			= BIT(27),
+	DRIVER_SG			= BIT(28),
 
 	/**
 	 * @DRIVER_HAVE_DMA:
@@ -129,7 +129,7 @@ enum drm_driver_feature {
 	 * Driver supports DMA, the userspace DMA API will be supported. Only
 	 * for legacy drivers. Do not use.
 	 */
-	DRIVER_HAVE_DMA			= BIT(28),
+	DRIVER_HAVE_DMA			= BIT(29),
 	/**
 	 * @DRIVER_HAVE_IRQ:
 	 *
@@ -139,17 +139,7 @@ enum drm_driver_feature {
 	 * drm_irq_uninstall() helper functions, or roll their own irq support
 	 * code by calling request_irq() directly.
 	 */
-	DRIVER_HAVE_IRQ			= BIT(29),
-	/**
-	 * @DRIVER_IRQ_SHARED:
-	 *
-	 * Indicates to drm_irq_install() that a shared irq should be requested.
-	 *
-	 * FIXME: This should be an explicit argument for non-legacy drivers, or
-	 * at least the default for PCI devices (which would cover all current
-	 * users).
-	 */
-	DRIVER_IRQ_SHARED		= BIT(30),
+	DRIVER_HAVE_IRQ			= BIT(30),
 	/**
 	 * @DRIVER_KMS_LEGACY_CONTEXT:
 	 *