drm/radeon: remove set but not used variable 'blocks'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/gpu/drm/radeon/radeon_combios.c: In function radeon_combios_get_power_modes:
drivers/gpu/drm/radeon/radeon_combios.c:2638:10: warning: variable blocks set but not used [-Wunused-but-set-variable]

It is introduced by commit 56278a8edace ("drm/radeon/kms:
pull power mode info from bios tables (v3)"), but never used,
so remove it.

Reported-by: Hulk Robot <[e-mail]>
Signed-off-by: zhengbin <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/radeon/radeon_combios.c

···
 {
 	struct drm_device *dev = rdev->ddev;
 	u16 offset, misc, misc2 = 0;
-	u8 rev, blocks, tmp;
+	u8 rev, tmp;
 	int state_index = 0;
 	struct radeon_i2c_bus_rec i2c_bus;
 
···
 		offset = combios_get_table_offset(dev, COMBIOS_POWERPLAY_INFO_TABLE);
 		if (offset) {
 			rev = RBIOS8(offset);
-			blocks = RBIOS8(offset + 0x2);
 			/* power mode 0 tends to be the only valid one */
 			rdev->pm.power_state[state_index].num_clock_modes = 1;
 			rdev->pm.power_state[state_index].clock_info[0].mclk = RBIOS32(offset + 0x5 + 0x2);