loader: allow 1MB device maps
There's no reason we shouldn't allow 1MB PTEs for use on device memory.

*** 161,175 ****
          if (ARMPT_L1E_ISVALID(*pte))
                  fakeload_panic("armboot_mmu: asked to map a mapped region!\n");
          l1e = (arm_l1s_t *)pte;
          *pte = 0;
          l1e->al_type = ARMPT_L1_TYPE_SECT;
!         /* Assume it's not device memory */
          l1e->al_bbit = 1;
          l1e->al_cbit = 1;
          l1e->al_tex = 1;
          l1e->al_sbit = 1;
  
          if (!(prot & PF_X))
                  l1e->al_xn = 1;
          l1e->al_domain = 0;
  
--- 161,182 ----
          if (ARMPT_L1E_ISVALID(*pte))
                  fakeload_panic("armboot_mmu: asked to map a mapped region!\n");
          l1e = (arm_l1s_t *)pte;
          *pte = 0;
          l1e->al_type = ARMPT_L1_TYPE_SECT;
! 
!         if (prot & PF_DEVICE) {
!                 l1e->al_bbit = 1;
!                 l1e->al_cbit = 0;
!                 l1e->al_tex = 0;
!                 l1e->al_sbit = 1;
!         } else {
                  l1e->al_bbit = 1;
                  l1e->al_cbit = 1;
                  l1e->al_tex = 1;
                  l1e->al_sbit = 1;
+         }
  
          if (!(prot & PF_X))
                  l1e->al_xn = 1;
          l1e->al_domain = 0;