PSRAM 2MB's EID indistinguishable from lookup failure (QEMU-239)

[muggenhor]

(Found this while reading through the code, so the bug report template is irrelevant.)

The EID lookup function returns the same number/constant for the error case as it does when requested to allocate 2 MiB of PSRAM:

qemu/hw/misc/ssi_psram.c

Lines 58 to 59 in 48b3fa9

	case 2:
	return 0x00;

vs error:

qemu/hw/misc/ssi_psram.c

Lines 68 to 71 in 48b3fa9

	default:
	qemu_log_mask(LOG_UNIMP, "%s: PSRAM size %" PRIu32 "MB not implemented\n",
	__func__, size_mbytes);
	return 0;

I.e. 0x00 == 0.

This causes this false positive error to be emitted:

qemu/hw/misc/ssi_psram.c

Lines 196 to 198 in 48b3fa9

	if (get_eid_by_size(s->size_mbytes) == 0) {
	error_report("[PSRAM] Invalid size %dMB for the PSRAM", s->size_mbytes);
	}

Project release version

48b3fa9