northbridge/intel/i945: Change types to uintptr_t where approriate

Prepares compilation for x86_64 by avoiding casts to different sizes.

Current patch fixes:
1.
src/northbridge/intel/i945/raminit.c: In function 'ram_read32':
src/northbridge/intel/i945/raminit.c:77:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   77 |         read32((void *)offset);
      |                ^

2.
src/northbridge/intel/i945/rcven.c: In function 'sample_strobes':
src/northbridge/intel/i945/rcven.c:29:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   29 |                 read32((void *)addr);
      |                        ^
src/northbridge/intel/i945/rcven.c:30:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   30 |                 read32((void *)(addr + 0x80));
      |                        ^

3.
src/northbridge/intel/i945/gma.c: In function 'intel_gma_init_lvds':
src/northbridge/intel/i945/gma.c:98:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   98 |                (void *)pgfx, mmiobase, piobase, pphysbase);
      |                ^
src/northbridge/intel/i945/gma.c:359:25: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  359 |                         (void *)pgfx, hactive * vactive * 4);
      |                         ^
src/northbridge/intel/i945/gma.c:360:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  360 |                 memset((void *)pgfx, 0x00, hactive * vactive * 4);
      |                        ^
src/northbridge/intel/i945/gma.c: In function 'intel_gma_init_vga':
src/northbridge/intel/i945/gma.c:384:17: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  384 |                 (u32)mmiobase, piobase, pphysbase);
      |

4.
src/northbridge/intel/i945/northbridge.c: In function 'mch_domain_read_resources':
src/northbridge/intel/i945/northbridge.c:64:23: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
   64 |         cbmem_topk = ((uint32_t)cbmem_top() / KiB);
      |                       ^

Change-Id: I5ac7a1cb5d85a346114f909047d5a7c21ddb43e9
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
---
M src/northbridge/intel/i945/gma.c
M src/northbridge/intel/i945/northbridge.c
M src/northbridge/intel/i945/raminit.c
M src/northbridge/intel/i945/rcven.c
4 files changed, 8 insertions(+), 7 deletions(-)